Id reccomend not only excersize but things that you used to do when you felt normal. Things that seem familiar (even tho memories might feel foreign to you, i get it)
For example: watch old shows you used to enjoy, even cartoons. I rewatched a bunch of old cartoons like ed edd n eddy, spongebob. Stuff kinda filled me with nostalgia and helped put my mind at ease. I also recommend video games, even if ur not much of a gamer, solving puzzles can distract you pretty well at times. Those kinda things might help stimulate some old feel good chemicals.
Read some book, meditate, things like that.
Also, even if you dont want to excersize vigorously, just a walk a day will help alot. I got dogs and having to walk them on days i didnt want to helped in the long run.
OH, this one may be hard for some with dp but this really helped me. Seriously, get out and socialize. Fortunately im blessed with friends who practically forced me to go out even though my dp made me so scared i could hardly leave my bedroom.
Thats about all i can think of at the moment, wish you all well.