Sounds like what you might need is a team.
A lot of these personal motivational problems can be overcome, or at minimum helped with having a motivated trusted group of people working with you.
We all have personal issues, we all have motivation dips, we all have issues figuring out what we want to do with our lives.
The problem with good games is they are addictive. It's a hard line to walk between addictive and fun. Some game developers understand that, others abuse their players. But that's another topic all together.
When you were playing these games, were you also thinking about how you cold change, or make things better?
If not, maybe creating games is not for you.
Anyone can play a game and spend hours on it, but a game designer plays and looks at the mechanics and components. working them in their head. Writing and drawing diagrams.
Games is an endurance sport. It's great if you can go fast at the beginning, but if you can't finish, or if you can't keep up a good pace, and update likewise, it can become a big drag.
Instead of going indie from the start, making your own game from scratch, have you ever considered modding? Modifying your favorite games?
That's where I started, and it can be less intimidating, and easier to find like minded people/ The down side, is you can't make money. It can be a good place to start, if your intimidated by the big games.
The other thing is you should stop comparing yourself to other people. A good friend once to;d me if you do that, you'll never win.
There was also a study done at West point a while ago. They put poor performers with ultra high performers, expecting the work habits to rub off on the low performers. What happened instead was the low performers fell even more, because they felt like they couldn't compete. They also put all the medium performers together, and it turns out they drew on each other a lot more, because they were of similar work ethic.
So as I said, find some people that are near your skill level, and try to work together for a while.
Also, this might be too personal, but are you on medication for your depression?
If your not, you should, especially given how much you've mentioned it. Depending on your healthcare, you might also want to get a counselor.
There is no shame in asking for professional guidance. Anyone who puts you down because of mental health issues is ignorant. Mental health is one of the biggest things in our society that people refuse to talk about.