I am sorry to read of your news. I think there is hope for you and I will explain some ways how, in addition to the helpful and sympathetic advice offered by others.
I am careful about this as all four of my grandparents have had malignant melanoma, I have fair hair and eyes, and I also grew up in the tropics. I am 32 and 3 of my 4 grandparents are alive (the other died of an aneurysm that wasn't related to cancer). The 3 who are left are in long-term remission, in their late 80s, healthy other than being, well, old.
There is absolutely hope for you. A diagnosis of cancer automatically qualifies you for state assistance in most states - you should call your Department of Human/Health Services or its equivalent. I think some hospitals will even do it for you. The radiation and chemo, if any, will suck, and it is absolutely time for you to quit alcohol/smoking/drugs. If you are aggressive in pursuing your options, you absolutely have a good chance at beating this. Even the emotional component can be addressed.
You did nothing to deserve this. Please don't blame yourself, whatever happens. And please get treatment. You have options and hope. My good wishes to you for a healthy life.