Stitched up too tight

So I had a baby vaginally 3 months ago with a 2nd degree tear and I still can’t have sex because it is too painful. I had a recent exam with my doctor and she said it looks narrow but that it could also be an infection of my uterus and gave me some antibiotics. I feel like I’ve been stitched up too tight and it is causing the pain. Has anyone else ever had this issue and what did you have to do?