well, that's rather relatable. i love reading, so i sometimes get a huge day long infusion of dopamine when i find a really good story and read it till i pass out. every new season in my favorite arpg is also a good time.
oh, also sleep deprivation. after like 20 hours there are a few hours before i can no longer stay awake where i feel better than the rest of the day. like my body no longer has the energy to feel bad and instead just reverts to normal, unconcerned brain states.
if you aren't already doing it, i recommend theraphy, as long as you are not american. it took a few months, but i can openly talk about all the incel related stuff during sessions and me and my therapist are on the same page most of the time. though i did slowly approach the subject over weeks and brought a folder with like 30 data graphs and quotes from studies to underline what i said. think being such an autist kinda helped there.
dont think sport is a good idea, I do it but constantly feel humiliated just by seeing all the way better looking people that i will never catch up to. I usually go in the middle of the night, since my sleep schedule is fked anyways.
honestly, i remember being young and just having fun even without people around and the big difference to now is that all the hope is gone and my outlook on the future is grim and depressed. hard to enjoy anything when you no longer believe things will every get better, not honestly deep down anyways.
think the only advice i could give would be: things will likely stay just as bad if you do nothing, so if you dont want to feel like this continously you need to do something, even if you have no plan and dont see any way how any attempt on your part could work out. though that thought didn't motivate me all that much myself until recently and I doubt the change I experienced will be relatable to you