J., My husband is a little like this. We moved here 5 years ago from NYC and he didn't have any friends here - only I did. We don't have a lot of free time and when we do he'd rather spend it with me and the kids. I, however, need some girlfriends. We had to have a big talk about it about a year ago and I had to let him know that as much as I love him and spending time with him I need time on my own and time with my girlfriends. This hurt his feelings a little and I felt bad. But in the end he realized that I was a better mother and wife when I'm sane - and I'm sane when I can be with my girlfriends.
As for finding couples that you can both get along with, I think this is the age old problem for couples. It has taken us 5 years to find two couples - yes two - that we really enjoy hanging out with. Other than that it's me hanging out with my friends. We get invited to quite a few get togethers and he chooses which ones he'll go to. I try not to make excuses for him though. I just tell people, he's not real social and doesn't like big groups - which is the truth.
When there's a couple that he doesn't like to hang out with, but our kids do, then I try to schedule kid activities and he can choose to come or not.
I know this isn't the easiest thing to navigate, but it isn't a marriage wrecker if you both talk about your feelings and you both respect the other's needs. He needs alone time with you, so be sure he gets it. You need alone time with your friends, make he sure he gives it. And occasionally he needs to suck it up and hang with a couple who bugs him. And occasionally you need to suck it up and turn down an invite to stay home with him.
Good luck!