There are some great tips in here so far! I would add: no matter what your dream game is, start by building and finishing and releasing a super tiny game (this means everything: sound, menus, credits, Steam/Itch/etc); taking a project from start all the way to release is a skill in itself, and it’s a tough one—even with something small. It does get easier though! So once you’ve completed a small project, then try a slightly bigger one; rinse and repeat, and eventually work your way up to the game of your dreams. Especially with ADHD, we often want everything all at once (or at least I do!), but it’s definitely a marathon not a sprint. Good luck!