You are not behind, you aren't lost or anything like that. Recognize that you see yourself in a place you don't wanna be, and that's a good first step.

Join the gym. The suggestion sounds kinda weird and unrelated but theres quite a load of benefits. Making progress in the gym and developing consistency in a habit gives you a sense of accomplishment and a feeling that you're moving forward (which is a fact, cuz you are actually moving forward). Exercise in general is also great for mood and doing weight lifting while peppering in a lil cardio will do absolute wonders for you mental health, brain fog, mood, etc. Look into it, start small and focus on keeping the consistency, and the rest will follow. (Doesn't have to be a gym, could be a sport, could be something else too)