Hey man, it sucks to hear you are going through these changes. Sometimes it happens that when a couple breaks up, one person takes the friends with them. It has happened to me before

Best advice I can give you is to put yourself out there and figure out ways to connect with people however you can. Sometimes when people feel sad they withdraw, which might be right for a little bit, but it can turn into negative feedback cycle where you feel insecure, so you don't reach out to people so you feel more insecure.

Play video games, go on hikes, volunteer, help people where you can. Keep enjoying life, whatever that means to you. Move forward. You will find this is just a bump in the road