AVM & Ischemic Colitis 24yrs old

I am looking for any suggestions or tips that anyone can give me that would be helpful. I am 24 years old with a history or depression/anxiety, ocd , and IBS, I pass out from time to time due to low blood pressure. I had a TIA 4 months after my c-section that was 3yrs ago. Now after a trip to the hospital and a colonoscopy I was diagnosed with AVM and ischemic colitis. I have had rectal bleeding off an on through out the yrs, and now I was told that its due to the AVM in the left side of my colon. My gastro Dr. wants me to have an MRA of the ab/pelvis, but there is one problem.... no one want to approve me for insurance and its over $2000.00 for this test. At this point I am at a stand still.. worried and don't know what to do. Please advice in anyway you can. thank you so much for reading!!