So confused...

I met my boyfriend of 6 months almost 7 years ago. We've always had a connection from day one, finally 6 months ago we started dating. My problem is he says he's in love with me and plans on putting a ring on my finger...yet he'll drink alcohol and say things like his relationships only last 1-2 years and not to be upset if he just ups and leaves one day...and also I don't think we've had sex with him sober more than a handful of times. I'm so confused! He acts all lovey dovey, but then says some screwed up stuff. What would you do??