What if you start to really like the new guy? Do you find him attractive? Are you open to the possibility that dating him "as a friend" might lead to something more? If that were to happen, then what course would you follow?

It sounds like you do not want to end involvement with the first guy, until - and unless - you have another relationship established. You don't sound too happy with your boyfriend. But I get the impression that the main thing you want to avoid is not having "a boyfriend." Like any guy is better than no guy. That's an approach that a lot of women take. I haven't seen it lead to happiness, but I guess it's a strategy for avoiding being alone.

I stuck with a guy who had a substance abuse habit. In retrospect, I'm not sure that was wise of me - even though he quit. I wouldn't recommend it. We all end up paying for our mistakes. I feel like I'm paying for mine and for his too.

I came to feel that being with someone seriously flawed was better than being alone. (By seriously flawed, I don't mean imperfect, which is true of all human beings. I mean flawed to where his life was just an ongoing mess.) Maybe that's your outlook, too.

The problem with hanging on to a deeply dissatisfying relationship is that it crowds out other possibilities - as you are finding. But, if you end it, there's no guarantee something better will come along.