Hi poppycat,
You sound just like I used to be...and you have a good idea of what bothers you and how your mind works. Yes, your mind can totally influence how you feel, anxiety even tricks you into thinking you are ill, when you are NOT. My husband used to say how many times I was anxious and nothing happened, and being so good at math, he figured that it is like 99.9999% I was anxious and nothing happened ( I didn't get sick). And yet I spent ALLLL that time worrying and feeling gross. I am much better, with therapy, good support, and meds. I would say keep talking to the professionals, find someone you like who will listen and believe you, and maybe try meds again. I think you probably get so anxious while taking them that you sort of cause a lot of the symptoms. Ask about ones with very minimal side effects. Take care and good luck, and welcome!