Not Endometriosis, so what is it?

Hello all,
I'm at my wits end so I thought I should try asking hoping someone else has experienced the same sort of problems.

When all the problems started, I was only taking the pill. No other meds.
I don't have any allergies that I know of.

Started with serious pains that felt like a UTI. Had blood tests and urine test. All came back clear. Dr put me on antibiotics in case it was ureaplasma.
Referral to a gyno, had pelvic xray and ultrasound. Also ultrasound on kidneys.
Nothing showed up funny except a bit of constipation and during the ultrasound they couldnt locate the left ovary, said it was due to gas or something.

The gyno also had a blood test done to check for some protein that is visable if it was endometriosis. Came back negative.

I've been on endep since then. Also took a liquid medicine for constipation and the gyno kept me off the pill for about a month. It seemed to get better.
I was having a burning pain around my vagina, not the opening. It seems a bit red in colour but not sensitive. I've been tested for all viruses and STIs. All negative. As well as the random burning I get a sharp pelvic pain on my left side.

As well as these ongoing problems I've been having random allergic reaction spurts. I get red blotches on my hands like the start of hives and the tingly itchy feeling.
I've also noticed since having these problems that after a shower my legs break out in red blotches.

I've probably left out alot of important points but. Lets just go with this.
My gyno had given me a referral to see a gastro specialist but I haven't been able to make an appt yet.