How to cope when everything in your life is falling apart

8 months ago I graduated college and the put me into a very dark depression because I LOVED college and my life there because i had a rough upbringing. I then got a VERY toxic job where I was bullied, micromanaged and sexually harassed by a man 20 years older than me. I mentally lost it so much, I would look in the mirror and not recognize myself. I was suicidal and spent most of my time thinking about it. I feel completely lost with my cancer path. I then lost my best friend because she said she didn’t have time for me since I graduated and she got a new social group. I was then told I might have cancer, got covid during Christmas and then got diagnosed with lymphoma cancer on my birthday. Its so aggressive that they didn’t have anytime to protect my fertility. It has caused a lot of stress on my family and relationships. It has caused my chronic autoimmune issues to worsen as well. I also have strong feelings for my best friend of three years but it’s gotten to the point where I think I’ll lose him because it hurts to see him with other people and it’s just another mental stressor I can’t handle anymore. If I stay friends I’ll be hung up and hurt for a long time. I’m at the point where I’m so overwhelmed I don’t sleep, can’t focus on movies or books. I see a counselor through the oncologist and it helps some but I’m just so incredibly disappointed and hurt I don’t know how to cope. I’ve been trying to focus on the good but it’s hard when your in so much physical and mental pain every day. Advice please?