I totally second this man. This advice is golden, and I had to learn it the hard way.
Indeed, I once fell into this trap of comparing myself to others -- and occasionally I still do -- but it's always important to remind myself that there's no (productive) reason to shoot myself in the foot. By telling yourself "I'm not as good as all these other people." all you are REALLY doing is telling yourself you're not good enough to accomplish your own dreams. Then who is responsible if you fail? -- You are.
I don't want to be a downer like some other posters trying to give you the "real talk" -- but I have been following the state of the industry since well before the late 90's, and despite huge indie-hits like minecraft making it look easy, if you're making games in order to both make money AND follow your passion, then, in a lot of (very real) ways -- you're running a fool's errand.
When developing a game all alone -- especially a larger project -- it's easy to become inundated by it! It's natural to want to make a thing "worthy" enough to put out there, and for that, you probably tell yourself "I don't want to make an arcade shooter -- I want to make that huge FPS / MMORPG / etc. / etc. I've always dreamed of! I can code and draw and whatever! I just need some help to make this happen!" However, although some people can accomplish a project with that kind of scope -- most people can't -- and even if they /can/ do it, I still wouldn't recommend it without seasoning your skills in all other required aspects of game development first.
Imagine you somehow pushed through to make that awesome-looking perfect MMORPG -- all by your lonesome! -- and then when it comes time to publish it, you realize you didn't know a thing about server maintenance or have a plan about how to patch the game or some flaw in your marketing technique bombs the number of users who sign up to play your game -- which means your game fails due only to your failure to foresee these tiny-but-critical areas that you might have seen had you analyzed user behavior in a much smaller title with online capabilities. Years and years of your life down the toilet all because of a fatal design flaw or lack of a necessary skill-set a simple game artist or programmer didn't realize he needed before he needed it -- which is a LOT more common than you might imagine.
The absolute worst thing you can do as a budding game designer/developer is fail to respect the level of discipline and years of skill-development that goes into even the most 'simple' of projects.
Even ol' Notch had developed a few smaller games before Minecraft (which itself was sparked from another slightly smaller game idea that wasn't even his -- Infiniminer) -- and Shiggy-Miya-MARIO-san (Miyamoto for short) still develops tons of tiny little "arcade-style" prototypes that find their way into his larger and more epic games (Zelda, Mario, etc.) As such, none of that effort developing an easier or smaller prototype game HAS to be trashed or meaningless -- after all, you learn something from it, and that's worth it alone -- but, when you try to market it (something you consider a lesser product) too -- you learn a bit about sales and distribution in the process, plus you learn about customer behavior and expectations along the way! All stuff that WILL be valuable to you if you plan to ever do it for the money. After all, did you know Shigeru Miyamoto-san actually believed Super Mario 64 had FAILED when he compared it to Tamagotchii? -- Yeah, me neither -- but check out the last few minutes of his GDC talk if you don't believe me -- It is truly eye-opening.
So if the undisputed master of game design himself can learn a thing or two (despite his skill level) from a game that is considered to be one of his greatest masterpieces, I believe we owe it to ourselves to study the discipline (and customer behavior if you're making games for money) first, before just "diving-in" to make games just because we have the tools on our computer to do it.
After all, without a LOT of study and networking, you will never have ALL the tools you need to compete in the market. I'm no expert, but I'm pretty sure it really is naive to think you're going to make a mega-hit without studying game design and customer behavior across the years to various game designs. No matter the quality level of your game, it can always fail -- even for the tiniest reasons -- and if you indeed think you have a mega-hit on your hands with your game idea, then it's highly-likely that you will have no problem finding help making your game a reality. But if all you're looking for is a sustainable living in the games industry -- skills are the most important asset anyhow -- and you generally learn those types of valuable skillsets by working on a game that is NOT your own.
As you're probably seeing now, "passion" does tend to run out sometimes -- and unless you thoroughly enjoy the creation process and do game development because you just find it genuinely entertaining, you'll find that a smaller game can get you farther with passion alone. A smaller game, too, has the added ability to showcase (and help you learn) some skills you'll need for a larger project someday.
The important thing is to COMPLETE something -- no matter how crappy you feel it is.
I worked on my "dream" game years ago (a small smash-bros-style platforming fighter), and although I was following my own advice on size/scope and thought I had everything figured out, it still turned out to be the game's DESIGN that kept kicking my tail (the ONE thing I thought I had nailed!) No matter how much I thought it was nailed before I announced it and started working on it, I could never find a way to balance the gameplay design without compromising the core objectives I had for the game (and therefore what I thought was fun about it) because I had later decided that, since I was already making the game, I could implement a good way of making money from it too, and thus became a core objective. However, in the end, it was the very idea of trying to make the design fit my ambitions of making it make money that caused me to back-burner the project indefinitely due to my passion for the project burning out. Once that goes, it is very hard -- and probably, really, impossible -- to ever truly and properly rekindle it.
I think the major problem you're having above all with your "feeling" is that you're creating a "product" and not that one thing you feel the world really needs to have above all else in a game -- that one thing you yourself really want -- but, as hinted at before, you might want to step back while the "passion" still exists.
Hone your skills. Get to be a badass at two or three important things in game development. Yes, this is possible simply with exposure and a LOT of homework and research. After all, everyone started somewhere. If you're still alive and kicking in a few years in this industry and have done the requisite amount of work, you'll have something to show for it. THEN put together a prototype and a team and start the project a LOT smaller than you'd be comfortable with now that you have a team. Not only will you likely have accomplished your goal, it will be more satisfying that your goal was accomplished than it would be to simply have accomplished the goal exactly the way you had dreamed it. Now not only will your dreams will be bigger -- but your courage and motivation will have grown exponentially as well. This is because your ambitions will have been made concrete. You will now know exactly what you are (and are not) capable of. -- You will never have to question your abilities or your project's worth ever again.
You will be able to do stuff you never dreamed was possible only a few years before.
Trust me if you will -- it's totally worth it.