I'm curious: what features do you need that none of the engines you looked at provide? If you don't feel like getting into it that's fine, but it might help people give you some more specific suggestions or to explain why a particular engine does in fact do what you want.
If you must do it yourself using C# look into MonoGame. MonoGame is a pretty popular library based on a thing Microsoft made called XNA which, while still usable, hasn't been updated in forever. You can find tutorials on the MonoGame website and also from google (having a specific technology you want to learn is easier to search for on google).
As always, start slow. Make very simple games at first (I'm talking solitaire, hangman, pong simple) and gradually increase the complexity of your projects until you feel you can handle your ultimate goal.