Help?! TMI but idk

I don’t know whats wrong with me. Me and my boyfriend have been sexually active for almost a year now, no problems, its great. The past couple of weeks it hasnt been. It doesn’t matter how turned on i am or anything, my vagina is a fucking cage. I’m super tight and no matter how much i try to relax or how much he tries to help, I’m still SUPER tight and i have no idea why. I started a new antidepressant (buproprion) and i already checked the side affects and the only thing maybe related is loss of interest in sex, but i am still very much interested, but i can’t relax. Has this happened to anyone? HELP