Step one is to be OK with mediocrity. When you pick up a game, you need to be willing to accept that you just don't need to be the best at it. If you can't accept this for competitive multiplayer games, you just need to find a non-competitive game. If you can't do this even for non-competitive games (this has been known to happen in the speedrunning community), then video games just might not be the hobby for you.

You can strive to improve, but you need to measure yourself relative to yourself alone. The best players of any game (whether it be the latest MOBA, a traditional game like chess, or even a physical sport like golf) put far more time into it than would be healthy for a non-professional. Even the average player that you play against likely puts more time into it than you should, because addicted people will play a disproportionate number of games.

If you can accept that you're not going to be the best, and just compare this game to your last one, that's the first step. The next (but not final) step is just good old-fashioned time management. You can get better advice on that from elsewhere, but it's important to have a system.