Why is my stomach bloated and hurting all the time?

About a month ago my stomach started hurting really bad. My stomach felt very queasy and I ended up throwing up the same night it started hurting. I just figured maybe I got food poisoning or something like that...well about two weeks after this my stomach was still hurting, still had the queasy like I'm going to throw up kind of feeling. I looked at my stomach and it looked like I was pregnant...no joke I was extremely bloated and my stomach felt very tight. I went to a doctor and he prescribed me Zantac. The doctor barely even looked at stomach, he just walked in pretty much, felt my stomach a little bit and that was it. But I'm not having any heart burn, it's just my stomach. So I'm not sure if it's acid reflux or not. Well, that was two weeks ago when I went to the doctor so it's been about a month now and my stomach still hurts and sometimes my stomach is still bloated. Yesterday at work I had a really bad pain in my stomach that came out of nowhere and went away after about 30 seconds. Did the doctor mess up?? What are some other reasons that would make your stomach hurt all the time and bloated with a queasy feeling? The doctor gave me a months worth of Zantac so I still have another two weeks worth of the pills but they just don't seem to be working that well. I only threw up the one time, but I feel like I have to throw up quite often. Any help would be much appreciated. Thanks.