I can’t find interest in people anymore

Sorry if this is a bit all over the place, I don’t use Reddit and it took me a solid 3 minutes to even figure out how to create a post here lol. I have always struggled being interested in things as a whole for long periods of time. I’ve struggled with this my whole life and never cared all too much because I could always just find a new hobby, game, one night stand, fling, etc. Now that I’m in an actual relationship with someone I can’t imagine being without, I’m realizing that now at 27, this applies to friends, family, and my girlfriend. I just can’t get excited around these people that love and care about me anymore. Everything just has to be new for me to feel excited. I don’t want to just replace these people and I’m afraid and constantly panicking because as I’m getting older, this feeling just seems to be getting worse and medication doesn’t seem to be helping. Any advice or suggestions is appreciated as i don’t know what to do. I’ve tried therapy but I haven’t been able to get anything out of it. Sorry in advance for the formatting