Small penis HURTS ME???

Ok I hope the title hooked y’all. I need HELP. I had my daughter in Feb 2019 and ever since, sex with my husband HURTS. Like fighting back tears hurts. I have sex maybe once a week now. Before my pregnancy it was fine, great usually. But as the pregnancy went on and I started to swell down there, it started hurting. HOWWWW can I help this? He’s not “big” but also not “small” id say around 6inches. I need serious help, this is a big issue in our relationship.