Aside from short-term physical pain, a number of fears may stick in your mind and put you off sex: fear that stitches will tear, fear of pain, fear that your traumatized body will kill off his desire, and so on and so forth. These worries are totally normal.
Talking to your partner about your anxieties will help to reduce them. Together, take it step by step and communicate! Make time for caressing and other forms of pleasure rather than penetration until you feel confident and ready for full sex.
If your partner wants to have sex but you don't feel ready, tell him that you're sensitive about it and explain why you don't feel able to respond to his desires right now. It's very important for your relationship that he doesn't feel rejected.
Another vital step which you must take is accepting your post-birth body.