I agree it is challenging building and maintaining friendships in adulthood. Also it's normal in my experience for them to wax and wane.
It's great that you have your husband and your pets! But yeah I get sometimes it's good to have people outside of family to be with.
What would you most like from your friends right now? Would you like to have someone listen to your problems or would you prefer distraction and just having some fun to take your mind off things?