Struggling to Get a Rheumatologist Diagnosis

I'm at the end of my rope. I really need to see a rheumatologist. It's non-negotiable. It needs to happen. the problem is that my city has a shortage of rheumatologists. I'm young, so people tend not to believe me when I say I'm pretty sure I have arthritis, despite my long family history of osteoarthritis, including my sister, who is 3 years older. My pcp is shit, but I can't get into my new one until August. I got my pcp to reluctantly give me a referral to the place my sister got diagnosed, but they gave me the runaround for a month before telling me that they don't take my insurance, which I know for a fact is false. I gave up on them. I asked for a referral to the main hospital in town, where the vast majority of Rheumatologists work in my city. My pcp VERY reluctantly agreed, and I was denied almost immediately. well, that leaves one rheumatologist in my area, and I was told my chances of seeing him a slim to none. I'm almost in tears, I'm do frustrated. I need to get a solid diagnosis, even though I'm 98% sure of what I have is the same thing my whole family has. If I don't get the diagnosis, I can't go on disability, and I need it. I'm really at a loss, I don't know what to do. As a last resort, there's a rheumatologist in a city 2 hours from here that I might be able to get into, but that might be a long shot. Advice?