I would set my standards higher. Just because a guy is interested, doesn't mean you have to take him up on the offer. It's stuff we know, but sometimes it seems less obvious when we're feeling lonely.

After a string of bad romances, I actually made a list of traits that signaled someone was going to be bad for me i.e. alcoholic, etc. If someone met ANY of those traits, I did NOT date them, no matter how attractive they otherwise seemed.

Maybe I missed out on someone good, but I wound up with my current BF of almost 7 years now, without subjecting myself to another miserable experience.