Who else feels this way?

It started as a gradual process but now Its become a part of me. I'm at a stage where I feel I don't have the strength to bond with anyone. I can comfortably stay for months without meeting up or calling any of my friends unless they call me to check up themselves. I have declined invites to a lot of get together, honestly I'd like to go but I don't find the strength nor excitement. I view family gatherings now as a burden. As a kid I use to be excited whenever we have a family gathering as a kid but now? I just wish the day would zoom off. A lot of people have tried to check up on me but my replies are sometimes cold. I swear it's not my intention. Later on when I realize I will feel bad and guilty. I have no strength for relationship. It wouldn't even work given how busy I am. Is this the direct result of experiencing numerous episodes of disappointments, betrayal from friends and heartbreaks? Or this is a phase everyone else passes through? Or this is who I am? I just want to know if it's normal.