Frequently urinating every time after sex

Hello. I'm new here and would like to seek some answers. I frequently urinate every after sex. It's painful, most of the time, and doesn't go away after a week or so. There's no blood and my pee looks fine. Only that I always feel the urgency to pee every 10 minutes, which goes on for more than a week. We have sex 2 to 3 times a week before, but sometimes just one as I'm beginning to resent sex because of it. It's very uncomfortable, not to mention painful. Please help. :'( Do you know any specific over-the-counter drugs that I can buy to ease the pain? I've tried cranberry juice and it doesn't seem to work. Thank you.