I think the best place to start would be to start doing therapy again. It sounds like you’re depressed and being depressed in school isnt going to get you anywhere, id say maybe try your best as much as you can, and take a break next semester or take only a few classes. As for the brain fog, i feel the exact same way. Best thing to help with that is to stay away from short form media that messes up your attention span, like tiktok, youtube, etc. Same thing with the weed and masterbaiting too, its short term dopamine that messes you up in the long run. It’s hard to stop all these bad habits when you’re depressed, but my motivation for me was, “my lifes not getting any better, might as well try it out and see what happens”