Cant be happy

Seems I cant be happy for anyone. Someone gets pregnant and i just think why should they be happy. Someone gets a good job and it's the same thing. It's been 3 months sense my miscarriage and its turned me into a bitter, morbid, constantly drinking person. I cant keep bringing it up to my fiance because he says forget about it why dwell on things but it hurts to much. How does ttc get easier?