Something is wrong with my body

I went roller skating with my friends today and I guess I put too much pressure on my arms while clinging onto my friend for balance. Or maybe I pulled it while falling. But it's been hurting all day. And it's not just that, I feel like I'm going crazy. My back, shoulders and neck and sometimes feet hurt every day, I've been in chronic pain for months. And my stomach has issues too. And I'm always tired and tense, having mental illness doesn't help that. And I get lightheaded if I get up too fast or do too much physical activity like running. It was worse when my ed was bad but it's still around. And I've always been so weak physically.

But I found a small lump in my armpit. And for months there's been a cut thats painful and never goes away. I'm scared and I don't know what to do. What's wrong with my body?