how do i bounce back from a breakup?

i don't really know what's prompting me to make this post. i just feel like i don't really have a place i can go to for any support or advice right now.

i broke up with a guy very recently because he'd engaged with certain things I consider huge deal breakers for myself. i really did like him but he had a lot of problems when it came to engaging with women he'd been involved with in the past or liked before. since the breakup, i'm finding it really difficult to perform any daily functions or even get out of bed - because of the sadness i'm feeling due to certain things he said during the breakup, the way i was treated and even intense guilt for ending things and hurting him in the process.

it's been around 4 years since my last breakup and i'm really unsure of how to bounce back. i try to distract myself by reading and watching shows and movies but end up getting upset within 20 minutes of starting a new activity. all i find myself doing is crying and sleeping and it's beginning to affect my health and nutrition as well. i'm someone with extremely poor immunity so i've started doing badly health wise as well.

overall, i'm just looking for any tips on how to restore my normal daily functioning. i'm currently on break - there's no work whatsoever i can engage myself in currently and i find myself at odds with the rest of my friends and family who are able to move forward with life. i just want to get a little better but i'm not sure how to do that. any help would be greatly appreciated