My now-husband told me that the only person that is ever with you for your entire life is yourself, and it made me laugh! I think a strength that we have is that we make sure that we ourselves are okay at the same time as looking after each other. He has certainly had my back while I've been through disfellowshipping and I've since even gone atheist and life has actually kept getting better all along. I think we'll do fine.
I don't have any other close friends either though; partly because I'm almost completely devoted to him, the fun we have together, and my studies (I'm doing an undergraduate degree finally!), but I've found that I've had to modify the way that I make friends with people. I can't just recruit friends from the three compulsory meetups a week; I have to make a real effort to get out of the house (and out of my head) and involved in things that get me in touch with people who like things I do. I've joined a gym, a scuba club, formed study groups, organised things with new friends at work. I never used to do that sort of thing, I used to just go out on the preach and meet my 'friends' there - people who now wouldn't talk to me because they disapprove of some choices I made. I far prefer my real friends, and I really like the person I'm becoming; somebody who works hard at being a good friend.