Struggling to Get a Medical Diagnosis

I wish someone in the medical field would take me seriously. I have Medicaid and a POTS diagnosis. All these problems started August 2021. My doctor blamed anxiety immediately, so I saw my psychiatrist and my psychiatrist said that all my symptoms have nothing to do with my prior mental health issues as I’ve been medicated for years and have had no issues since being medicated. I argued and cried in front of about 7 different doctors before I got a POTS diagnosis at my schools student wellness center. I haven’t seen a doctor since May and I’ve been having many difficulties for months. A cardiologist laughed at me and humiliated me, waisted my money and time. I can barely walk to work or class. I just got myself a wheelchair off eBay to help me out on the really rough days. I haven’t talked to a doctor about that yet and I’m worried to. My self esteem has suffered so much from all these experiences. I can’t sleep because how uncomfortable I am. I’m so bloated I feel heavy. Eating is a struggle, I’m eating a clean gluten free diet. No junk, mainly ingredient based meals. No matter what I do it’s either vomit or diarrhea. Every time I move I feel dizzy and lightheaded, I rarely feel coherent. Standing is worse. It’s like every-time I stand there’s a 15 minute countdown for me to sit again before I pass out. When I’m completely free all of substances and medications I feel as if I’m doped up on something. I’m always so miserable I just want my life back and I have no idea what to do about it. Medicaid assigned me to a pediatrician and I’m a whole ass adult. I have no energy to argue with doctors or Medicaid. Why does this shit have to be so hard.