Hello , I Have One Question. I Am A 33yrs

Hello , I have one question. I am a 33yrs women , when ever I had sex , didn't have orgasm. Why can't I have orgasm during sex? To be specific, I am over weight and worried that's affect. I do finish when I use self satisfaction. What can I do. Because of that, I hate sex and that's a big problem between me and my husband. Thank you