Leaving an old friend

So me and a friend that I've had for around 6 to 7 years has become really toxic towards me and has been being really distant and I haven't really done anything to them so I've been thinking about it and think that it's best for me to straight up just leave the friendship. The  only issue I keep running into is that I rely on people around me to keep me happy and sane so when I don't have anyone around me that I'm used to, I start getting very upset and depressed. So I've been trying to work through that as well as trying to think of ways to fix the thing that me and them are going to a Nascar Aloe concert to go to on 9/11. I guess I'm going to have to go through it until after the concert. Because when I asked them to go on a walk with me last night and told them my normal joke stuff like, "Bitch wake up and charge your phone now/j" they told me that they were actually going to sleep and that they couldn't go out at all. Like they usually can't go with me but the way that they said it was hella bitchy. I get that friendships separate but this one is going to be a lot harder to get through than any other friendship that I've been through. I guess I'm just gonna have to roll with the punches.