Ulcer or Gallbladder Problems?

I have had a peptic ulcer since high school and a history of a dodgy stomach since I was 11. The ulcer was usually tolerable until this summer, when a period of intense stress resulted in a flare up. I went to the ER, went on a regimen of Prilosec, and the ulcer calmed down, giving me very few problems after about a month.
However, lately I have been have a lot of stomach issues. Foods that have never bothered me are suddenly making me sick to my stomach. And the nausea is worse than ever because it is now accompanied by dizzy spells and lightheadedness.
My roommate swears its gallbladder issues. She recently had hers removed and says I have all the symptoms she did--sore back, cramps (not menstrual), and tenderness under the left side of my rib cage. Also, the foods that really make me sick is anything fried or with the slightest bit of grease to it--such as melted cheese. But not salad..
There is a history of GB problems in my family..how do I tell what is bothering me?

Honestly, you should always check with a doctor for anything medical!
But this past March, I was having really bad stomach problems like the same ones you describe...In May, I had such problems that I went to the ER two times. Everytime they gave me some pains meds and said it was an ulcer. Finally, the third time I had an attack, so bad I thought it was a heart attack, they finally an ultrasound and said it was my Gall Bladder. I had surgery two weeks later and have been fine ever since.

You need to go to a specialist and they will do test, do not wait until you are in the ER. Get it taken care of beforehand.

Only a doctor is qualified to say-but it sounds like gb stones or other related issue.