Hi @Frilled-Lizard and welcome to the forums
I hope you are able to find some comfort here. I have found the forums to be friendly and supportive.
I have been lucky in my life with physical illnesses. I have had complex trauma (cPTSD, anxiety and depression) since I was a child.
About 3 years ago I was diagnosed with cancer, caught early though so just surgery and radiotherapy.
At a f/u scans some "things" were found and it turned out I had another cancer and a rare immune disease. So more treatment. I currently take treatments for cancer and the rare immune disease. However, I am lucky that these don't impact me too much and I am able to do pretty much anything I like including sport. I am on the older side and now I have arthritis, but I keep moving to try and keep that from impacting me too much. In the last year my father came to live with me and I was his sole carer until he passed away from cancer. When Dad was here I could have 8 medical appointments a week between the two of us.
I suppose I try not to let things limit me too much and I sort of just "put one foot in front of the other". I have actually found the physical illnesses easier to deal with than mental health conditions. However, as I say, my physical conditions have not been long lasting so far. The arthritis and the immune thing will be chronic diseases, but I've only recently been aware of them. The immune thing can affect any part of my body, so far it's only limited to two organs.
I try to keep active, I try to do exercise, I try to eat well, but I do sneak in the odd treat - like chocolate!
I volunteer, now that I've retired. I try to have social contact, I do a bit of music (badly) in a class. So I suppose I use a bit of distraction and try to find purpose.
I am aware of a few people on the forums who have chronic physical conditions as well as MH condiions. So you may get some other points of view, suggestions etc