Constant nausea, along with other symptoms

H'okay. I've been waiting since 12:30am to post this.

I have been to three different doctors, and nobody could tell me what's wrong. I had a blood test done recently, and nothing showed up. (other than slightly high red blood cell count)

The syptoms:
Constant nausea, feeling of fullness, no appetite, stomach spasms, gurgling in stomach/chest. and slight cramps.
Spasms and piercing pain in the intestinal region, along with a bit of constipation. (maybe from not eating enough?)
It feels as though there's a lump in my throat.
Chest pain, sometimes piercing, sometimes pressure, but rarely around my heart area.
Worse at night.
If it's really bad, I'll start to shiver and twitch severely.
I have not thrown up nor gagged, but it feels as though I may.
I also have a shortness of breath, constant yawning, and taking deep breaths.
Lastly, I have a severe intolerence to ceratain foods as of late. Garlic, tomato, pepper, smoked foods, olive oil, greasy/fatty foods, aspertame, foods packaged in cans or foil, chocolate, caffiene, bread, and dairy. (most of which I normally eat daily)

This has been going on since October 30th. It was worse around November 10th-20th, when everybody in my house got a bad stomach virus. Now..could this be a sort of mutation? Maybe a parasite..or do I have to worry about heart trouble? There is no pain on my right side, so I don't think the gallbladder or appendix is the cause, but I'm no expert. Despite everything going on right now, with my dad getting married and my mother possibly having cancer, I'm actually not stressed about anything save for what's wrong with me. I may also note, since the doctors ask, that I do have allergies and I do own animals. I have two lizards, three cats(two of which sleep with me) and a sugar glider. I don't feel any better with the cats out of my room or Scout's cage cleaned. I may also note that some of my lizards died recently. (two of old age, one of parasites she got from the pet store) I had a bout of insomnia in July, and didn't really get over it untill I got really sick. Now, just before the insomnia, I moved my iguana to a wire cage. She still had the bugs, despite doing everything I could to get rid of them. She fell ill around the same time that I did, oddly enough. Maybe I got something from her? I also keep my hands clean after handling the herps, though I will sometimes let them out for a while, and, admittedly, I may have an itch on my face that I instinctively reach to scratch, without thinking.

I really need to know what this is..and preferably avoid Mr. Endoscope. (though I'm willing to go through anything right now) This has just been going on too long; I'm 18 and I still have a lot to do in the ways of school, and this is really slowing me down. I've already missed too much. This is scaring me..if anybody can help, I'd really appreciate it.