I’m gonna get you … diagnosis

I was in my twenties when my health fell apart, in many ways similar to what you're going through now. The triggering event was my catching mono, which decimated my immune system and led me to develop a bunch of other illness, then I had awful reactions to the various drugs I was taking for my many illnesses, and I developed bad hypochondria from being so sick all the damn time. (In other words, I was so sick in so many ways that it made me obsessed with sickness and terrified that every new sniffle was going to turn into yet another horrible illness). It was hell, and while I've had better times since then my health has never been good again. (I'm not saying you'll be sick the rest of your life; that's just how it seems to be working for me.) Here are a few things I learned from being hideously sick in my twenties, and continuing to be pretty damn sick in the years since: Get in the best shape you can, while you're young. Exercise, eat right, all that annoying crap. Do everything you can to build yourself up. Find doctors you can really trust, and just do what they say. The alternative is to run around from doctor to doctor, exhausting one doctor after another and never getting any damn answers. (Doctors do have a way of just giving up in frustration if you keep showing up complaining about how you're in agony and you can't live like this.) Do everything you can to make sure a doctor is trustworthy and smart and compassionate and awesome, and then put yourself in their hands. It's frustrating and it feels too passive, but that person is a doctor and they do know more about medicine than you ever will. Try to resist the impulse to be your own doctor. You'll read a lot of things where people tell you that you have to be engaged, engaged, engaged with your own treatment, but in my experience that just makes you terrified and it frustrates the hell out of your doctors. DO NOT go wandering off into the web forums where people crab about their exotic, life-destroying illnesses that sound a lot like yours. That shit will make you miserable. You don't know you have the same disease, those people have the worst case scenario for their disease (that's why they're crabbing in forums) and the advice they offer will contradict your doctors and confuse you and might even make you sicker. NO WEIRD ILLNESS FORUMS EVER. Look into a doctor's history, read every Yelp review, do everything you can to make sure that doctor knows what they are doing, and have a visit to check out their bedside manner. When you find a doctor you can trust, just let go, and let them steer the ship. Take the minimum amount of drugs possible. Follow your doctor's advice, but try to eliminate a drug as soon as you can. Every drug has potential side effects, and side effects mean more sickness. (In some cases, that sickness can be worse than your original illness.) If you are prescribed a drug, research it. If something about it seems questionable, ask your doctor or pharmacist. Be careful about complaining too much to your friends and family. You are probably a roiling ball of misery right now, and that's hard on other people, especially people who have never been sick and scared like this. People you love may give up on you, and break your heart. Do what you can to avoid ever getting to that point. Try to be strong, always. Never become a Debbie Downer, endlessly bitching, no matter how much it feels like your life is nothing but problems. Do everything you can to hold on to your career. Work part-time, go to school, anything. Don't let your illness leave a big black hole in the middle of your resume. And don't let your sickness rob you of happiness! Spend time with your friends and family. Go dancing. Go to museums. Do creative stuff. ENJOY LIFE, as much as you can. TLDR: Work out and eat right. Find a good doctor and trust them. Be very careful with your medications. Don't complain too much. Don't let your illness ruin your career or prevent you from having any fun at all.

Despite your therapist's certainty that there is a mysterious physical issues tying all this together, have you and your GP considered http://en.wikipedia.org/wiki/Somatization_disorder? For some background, http://www.amazon.com/exec/obidos/ASIN/B000GCFXCM/metafilter-20/ref=nosim/ is good.

Can you get a referral to a rheumatologist? I have no idea if what you're describing is autoimmune, but a rheumatologist may be able to piece together what is going on or at least give you a better direction to head in. Endo isn't a bad idea either, but if your thyroid levels are normal (TSH too, right?) I'd probably start at rheumatology first.

Nthing rheumatologist. Women are more prone to autoimmune disorders, which tend to manifest in one's 20s, and autoimmune disorders can be very hard to diagnose. I've known women who have had to go to several rheumatologists and spend quite some time getting a diagnosis - but, luckily, there is a lot that can be done to alleviate the symptoms in most cases.

(N+1)thing rheumatologist. A lot of the symptoms described sound eerily similar to my wife's experience. Her neurologist tested her for lupus using what we understood to be the primary indicator and she came up negative. The neurologist suggested that we go to a rheumatologist anyway. The rheumatologist confirmed autoimmune problems and eventually lupus using other tests. She's responded to treatment pretty well.

In addition to the suggestions above you might find a registered dietician with specific expertise in IBS and explore a FODMAP diet. We have a family friend with IBS and this was really life changing for her. Good luck - what you are going through sounds beyond tedious.

Have you been tested for Lyme disease? Have you been in the northeast?

When they did the bloodwork, did they test your vitamin B12 levels?

Have you tried any kind of elimination diet? FODMAP is one you may consider. If most of your symptoms are GI-based, food is the first place you can start, and the one thing you have the most control over. Anecdotally, a friend of mine has a nightshade allergy, and when she is exposed to nightshades (through seasoning at restaurants, usually) she has a lot of the symptoms you describe, especially the spiraling anxiety.