I don't know what is wrong with me

I'm 19 years old.  I was very very active and athletic and was able to eat almost all foods.  This was up until about a month and a half ago.  I started having bad intestinal problems (burning, stinging, painful).  I couldn't eat much.  I've had bloodwork done four to five times, a CAT scan, two stomach x rays, an ultra sound, a colonoscopy, and an endoscopy.  They discovered inflammation in my colon but not bacteria.  It's not celiac or an h pylori infection.  Since then I started taking hyoscyamine.  It made my mouth dry and my vision blurry.  Then I stopped taking it and started wondering if I had HIV.  I recently got tested for that and I am awaiting the results.  My symptoms now include swollen lymph nodes (back of neck, under chin, and groin), tingling in my fingers, my legs are uncomfortable when I sleep (and they have almost always been like that), my muscles twitch, my muscles get tired really easily nowadays, I'm tired almost all the time, I don't have a fever, no cold, no flu (i'm pretty sure), and theres still a burning near my lymph nodes in the groin, but it might be because I poke them a lot and ride my bike and it irritates them.  I have always had back pain even though i'm active and knee pain.  I also get dizzy when standing up and lightheaded (I recently got glasses for this).  I have a low IgA count and low iron.  My eye sight was always fine until a few months ago when I started getting headaches.  I use to be so happy and active, and now look at me, I'm falling apart.  Please help :(