Feeling miserable when I should be happy

I’m exhausted and sad. I have everything to be happy and that makes me feel even worse. I’m 6 months pp with my family and friends in a different continent and most of the day we cannot even speak on the phone. I have no support network, I only have my husband but he works all day. I spent the whole pregnancy alone and I’m alone all the time with my baby, I feel miserable. I don’t know how to change this feeling, I’ve grown bitter and resentful, but most of all I carry an incredible amount of guilt for missing my old life so much, I used to feel I was the happiest person ever, I enjoyed life and felt I was at the best time of my life. We wanted this baby even if it came faster than expected and I love my baby but I hate my life right now, I’ve been waiting for this feeling to go away but sometimes it grows stronger. I don’t remember the last time I felt happy, I want to have a genuine smile again.