Could you please answer this?

HI, I used to be friends with some people and I thought we still were but it turns they are not too bothered with me anymore for no apparent reason. I see them everyday and at first I tried being friends with them and talking to them (a lot of times) but they seem aloof and have other friends they talk to. We were like old school buddys and it just hurts everytime I see them. I have accepted it but I would rather not see them but I haven't a choice. Do you know a way how I can not truly care about this? I just want to be happy but I get down when I see them...