Lonely

My husband and I are 25. Our daughter is 9 months and NONE of our friends from college have kids or are even married. We feel so left out. Like maybe we rushed into this marriage and kids thing. Our friends stopped checking on me and my husband and go out and do their thing. We no longer get invited to go on shopping trips, lunches/dinners, movies, our lady night, etc. When I think about all the friends I've lost and all the fun I could be having I get really sad. I want to address this issue with my 'friends' but have no idea how to go about it. I don't want to blame them but I want them to realize I want to be included in things from time to time. What should I say? TIA ladies.