Your boyfriend is an alcoholic, and headed for serious liver problems if he doesn't already have them. Throwing up blood is a very serious symptom. If he continues to drink there's a good chance he will die from it. I'm not a doctor, but my second husband had liver failure and I learned a lot about it.
There is nothing you can do to "fix" it or to "help fix" it. If he wants to drink--and alcohol is alcohol--beer is no safer/better than vodka--this will become progressively worse.
As far as your own drinking goes, I'd recommend you stay away from it. Normal drinkers do not "black out," even if they've had a lot to drink. There's a good chance you will develop your own alcoholism if you continue to drink. My own alcoholism developed much later in life, but I know many people who drank alcoholically from almost their first drink.
In addition, drinking with him is a form of enabling.
I'd suggest you find an Al-Anon group near you and start going. Al-Anon is for family/friends of alcoholics, and it isn't to help the alcoholic get sober but to help you recover from the effects of living with someone else's drinking.
I get that you love him. Alcoholics are not horrible people. The thing is, you are very young and you can waste years/decades of your life cleaning up after this guy. I loved my second husband. I loved him when I left him, but it was a matter of self-preservation. I'd seen him through one near-death experience, and I wasn't up for another when he went back to drinking after nearly dying of it.