mental exhausted almost everytime

hello guys! i do have ocd and currently have mental exhaustion most of the times and sometimes physical. majority of the times if i workout i feel worst, i need naps, feel really tired, lazy. right now im in my sofa with mental exhaustion. i sleep around 6 hours a night and naturally wake up at around 6 am. i am constantly thinking and right now i feel like i don’t know what to do with my life when it comes to what to study. i got a bachelor in something i don’t like much and im 28. anyone else have almost or had these experience? i do bodyweight workout 3 days per week and walk around one hour 3-4 days per week. if i do stop bodyweight stuff i think i feel better. why?