Best advice I was ever given: “Just don’t quit.”
Keep at it, year after year. You are doing good work already.
I’ve only skimmed a bit here and there - but if you don’t mind a small suggestion, and take with a handful of salt - consider putting aside things that only make a visual difference for later and try to get a completely playable game with start and win/lose state as soon as possible. Because the visuals will have to change to accommodate the gameplay and after playtesting you will no doubt need to make many adjustments. If you put a lot of time into stuff that is only visual, then when you have to redo work it will create serious heartache.
My rule I try to stick with is that I playtest a complete round of my game every day. And try to get it into other peoples hands as soon as possible. The biggest gains come from playing the game - that helps you really figure out what it needs to become. Then putting on all the bells and whistles at the end can be a great joy.
Just some advice, may not fit in all cases but it’s helped me manage the mood swings :).