Listen to this man. My grandma had a severe case of breast cancer and melonoma 8 years ago, and she's still around today. She had strong family ties and is very religious. Set goals for yourself in the future (like starting a family, working out, visiting other places of the world when you're 30). Be optimistic and you will beat this.
You're in my prayers, and we all are supporting you here.
Best thing you can do is just keep positive, i know its hard as fuck but trust me, my family is like cancer central, my mum most recently just got the all clear after her breast cancer tratment, you can come through.
As you said, they've been researching their drugs for awhile. If they're up to the clinical trial stage. You'd assume that there'll be strict FDA (I think it's FDA in the US) guidelines for the drug in terms of safety. Try and find out more about their treatment, and definately get the advice from your doctors. I know of (not personally) cancer patients who have gone on drug trials because "it won't hurt anyways" and that it may be a more effective treatment. But yeah, talk to your doctor more about it.
I suppose you could think yourself lucky for the ulcers after all. If they hadn't of found the cancer then, then who knows how far it might have progressed before they did? In regards to the time frames doctors place on things such as this, you should keep in mind that this is usually a worse case scenario thing. An uncle of mine was diagnosed with a pretty severe lung cancer and given about six months to live. Five years, multiple operations (with general anaesthesia in a very weakened state) and two amputated legs later the guy's still going. So all the best of luck to you; a healthy mental state is very important so try to stay as positive as you can.