Peptic Ulcer Problems?

So about three weeks ago, I had to go into the ER for severe stomach pain after eating some fast food, thinking it was my gallbladder or something. I never threw up, but It just hurt really bad, in my upper abdomen below my sternum.
They ended up ruling everything out and decided it was an ulcer or gastritis.
That eased my nerves for the time being, and I started taking famotidine at the beginning of last week to take care of it. But I am still having stomach pains when I don't eat or when I "breathe through my stomach" deeply in my upper abdomen.
I also looked it up and saw that an ulcer can eventually kill you.

So my question is, am I at risk for severe stomach bleeding from the ulcer? I am 18 years old, very stressed out everyday, I smoke off and on, (maybe one every couple days) I am 5'11 and weigh 130 pounds.

(Also, does famotidine help heal ulcers?)

Thanks.