Sharing Our Innermost Thoughts

It feels so wierd to reconnect with people who were sp close to you at some point right? Even if you try to reconnect it doesn’t happen sometimes. There is a senior of mine who was very close to me, he was like a mentor to me. We use to talk alot about crazy stuff and I was always sure that no matter what happens he will guide me. But last year after October or something I suddenly stopped talking with people as i was in a kinda situation where i wanted to just be away from everyone. Due to which I lost people,friends. After like 6 months I talked to him again but it was not like before. I mean even when i was in that period of not talking to anyone, he never contacted me too, may be he was busy too. But here I feel guilty of not talking first, he is a very good guy and I respect him alot. I want to talk with him just like before.
Its not the first time, there was this girl who was my very close friend, we were like best friends. I use to visit her parents and be with her, go out for movies and all. Later she moved abroad but still we were in touch, she cam back to india for holidays and we were supposed to meet and a shocking news of my mom death came to me and i had to go to my hometown. I told her everything, she went back to abroad and told me to contact her when am all good. But i was in depression and didn’t wanted to talk or bother anyone and even she never contacted me at all even to ask about my status. After 5 months of not talking I messaged her and she sounded so different like a stranger. In that meantime alot has changed in her life and also mine but she didn’t say anything.
I don’t understand is it my fault?? Why do i lose people??