TMI, poop problems??

Ever since I was born I’ve had bowel problems. I was allergic to formula and my poop literally burned my skin. When I was 4, my mom had to take me to the ER because I was so constipated. I’ve never been diagnosed with IBS or Chronic Constipation. But to this day (I’m 19), I get constipated all of the time or I don’t fully release. I’m pretty sure I have a prolapsed bowel because of constantly having to push, to the point I’ve blown the capillaries in my face countless times.

I’ve tried miralax and even herbal teas that are supposed to help. I’ve tried changing my diet and being more active. Nothing I’ve tried helps. The only things doctors say are “eat more fiber and drink more water.” Which can help some people, but has never helped me. Even when I was the most fit, active and hydrated person, I still had these problems. Any tips would be great.