Worried about upcoming rheumatologist appointment

I am 38 years old and have a long history of strange symptoms (going back 15+) years. Mostly struggling with skin rashes and GI issues. About 5 years ago I had a bad flare up and saw a rheumatologist who completely gaslighted me and left me in tears. She told me it was all in my head and I needed mental health support. I then went to a holistic practitioner and was able to gain some relief and told myself I was going to be fine. She treated me for an imbalance of gut bacteria. Fast forward to this year, I have developed a burning rash on my left arm that will not go away. I saw an allergist who told me it was not eczema and she could not help. In September I ended up in the emergency room with pericarditis. I have developed numbness and tingling in multiple extremities that they have yet to be able to pinpoint a source for. I had a MRI and EMG that shows a likely pinched nerve in my neck but does not explain the numbness in my feet. I have developed pain and inflammation in my knees, elbows, wrists, and feet. My elbows look and feel bruised and they have been like this for weeks. I saw a rehabilitation specialist who diagnosed me with multi site bilateral tendinitis and has put in a referral for a rheumatologist. I also recently developed mild Raynauds syndrome and livedo reticularis around my elbows. I am so tired all the time and have to force myself to continue to eat. My concern is that the blood work that was ordered at the time of this referral came back all normal besides elevated segs on my CBC. Negative RA factor, negative ANA, normal inflammation markers. I am so scared that the rheumatologist will just dismiss me once again. I don’t know what is going on but something is clearly wrong and I need help but I don't understand how nothing is showing up on my blood work. I don’t want to be sick, I don’t want a chronic illness, but I want someone to believe when I say I am having pain and can’t live like this. I just wonder if someone else may have had a similar experience where blood work “looks normal” but they were still able to get a diagnosis. I have added some pictures of my rash and joints. Thank you.