Best friend gone off the deep end

I need some advice. My best friend has been going in and out of hospitals for mental health reasons. She has always been sort of negative and over dramatic about things. I am finally happy with my life and where my life is going and my new job and just everything! She just recently got out of the second hospital she was in on Friday and really wanted to hang out yesterday but I kind of blew her off. I’m worried that she will bring me down and I don’t need that kind of stuff in my life anymore because I’m finally seeing a light at the end of the tunnel so I can be happy! I don’t know I know this sounds selfish but would you still be friends or just let them figure themselves out before hanging out again?