My husband is OCPD. He isn't what people would typically thing of as one. He isn't a hand washer or a door locker. He does do repetative behaviors, but they are more random (with the exception of coming in and out of doorways or up and down stairs - he does those all the time) like when he sets his cup down, picks it up, sets it down again, picks it up, sets it down until he does it "just right". He will not step on a crack, he will count the tiles between his steps, he can't handle changes, freaks out if he makes a wrong turn or gets slightly disoriented. I won't let him drive with us in the car anymore after too many "We're all gonna die!" statements while we were in the car. So, I feel ya.
He does have friends, but it might be easier because he is in the military and trust me when I tell you they appreciate his attention to detail and following regulations to the letter. Who you work with is who you hang with so he is well loved.
Since you just figured all this out, let me help you with some things I do to help him:
I set up social things for us, so that he does get out and do things. He is almost always initially resistent, but then he ends up enjoying himself in the end. Staying in the place he is most comfortable isn't necessarily the best thing and he needs to regularly be reminded of the rewards of relaxing.
I have talked to him about what I see and I have told him what I think it is and I have shown him documentation to support that. It was a relief to him to know the why of what he was doing, and he was much more willing to have me "help him" when his issues are controlling him instead of the other way around. Before he would just get embarassed and defensive, and now he lets me say, "it's ok, put the cup down."
We do our best to work around situations that set him off or make him overly anxious, because OCD is an anxiety disorder, so the more anxious he becomes, the more rigid he becomes, the more repetative his behavior becomes and the more miserable we all are. For example, transition times are hard for him, so if when we went to the beach for the day, I sent him out to get cups, sunblock and a couple of other things. I stayed up the night before and packed the bags, and made the sandwiches and while he was gone we completely packed the car got the little kids dressed in their bathing suits and clothes, the big kids got dressed, I got dressed and when he got back we were all ready to go. Crisis averted. Then I drove and he just rode along. I get directions to where we are going, I set the navigator, I make the phone calls, I do all the planning because he gets lost in the details and if the plan changes he wigs out.
As to your daughter, have you had her evaluated? If not, then you should. You are in an excellent position to help her aquire skills to deal with others and cope with her anxiety. She would benefit very much from therapy to help her understand why she feels how she feels, how to cope, how to make friends, how to keep friends. That's what I would do to help her, if I were you. It looks like our son is very similar so I will be doing that before long as well.