Part of your depressed mood could be compounded by withdrawal that your body is going through. If he's spending time drinking and not working, does this mean he isn't secure with a paycheck?
8 years of not being sober brings your age to 16 when you started with that lifestyle? I ask because it leads me to question what your relationship may or may not be like with your parents? Do you have extended family? What about adoption services if abortion isn't sitting well with you? Does your bf know? Does he want to be the type of father for this child that the child deserves? Will he change his not so sober ways to coparent?
Lots of things to consider.