What would you do?

Me and my close friend have drifted apart. She’s my only friend and after she got a bf and new friends thing have changed. We don’t see each other at all. Sometimes We talk every day. Sometimes she takes days to respond and when she does respond she acts like she didn’t just ignore me for days. It’s getting kind of annoying at this point because I feel like I’m always the one to put in the effort. Should I just give up and let her go?

Update: When I used to hang out with her she would always text back her friends asap. Cus she would always be on her phone and I would recognize their names.