Quoting Chim Richalds:" Unfortunately it happens at any age . It's rough at first, but once your LO is up and wanting to ... [snip!] ... other moms everywhere you go pretty much. Or you could look for playgroups around you, mommy and me classes, meetup.com, etc."
When I lost my "friend" due to pregnancy, she was no longer interested in me because I could no longer do the things she liked doing.
I met a mommy friend off facebook. She has three kids and is a SAHM like me so it is MUCH easier having her there. She knows what its like being busy and we hang out at each other's houses drinking wine and watching shows. MUCH better then going out to a bar, knowing that if you drink, you wont be able to take care of LO in the morning.
Just try find a mommy friend. Friends come and go.