Stay together or move on?

I have been with my partner for four years. I have 1 child from a previous relationship (5 years old) and 1 child with my partner (10 months old) but both know him as their dad. I am currently being treated for post natal depression and I feel at the age of 25, I have nothing but regrets (apart from my children I love them so much). Things were great for the 1st year of our relationship but after that, I seem to be the only one who still makes an effort. Things worsened two years ago when we moved in together. He isn't interested in going out, never says nice things or does anything romantic etc, most of the time he isn't even interested in us having sex. His mum says that she had a similar life with his father, very regimented where he would make an atmosphere and she would be on edge. As I have PND, I don't feel I can cope with the negative atmosphere and constant criticism of me and my oldest son from my partner. It has come to a point where, even though I really do love him, I can't take anymore. I have given up so much to be where we are now and I don't want to regret it and waste anymore time if he doesn't feel the same or he won't allow us to be close like other couples I know. I want to be with someone who maks me feel special to them and treats my son with encouragement etc. I have tried to tell him how I feel but he just ignores it as if he just doesn't want to know and things can carry on as they are. What should I do? xx