What do you do when your in a rut and mentally don’t want to deal with life?

I (20M) have spina bifida and hydrocephalus, despite this I exercise 5 times a week ( 3 days weightlifting, 2 days cardio and boxing). I volunteer for my local park twice a week aswell. My problem is my lack of drive to do all this. I used to thrive off it , but lately I’m just going through the motions and feeling unhappy about life in the sense that I’m doing all this yet all I want is to not be lonely because even though I see a lot of people everyday , I still feel lonely . The volunteering work has collapsed due to friction within the group, so nobody has any motivation to work anymore. I feel like I let myself down for every day that I stay the same .