Sex: what am I doing wrong

Kelsey • 21 years old and single
Me and my boyfriend have been together a little over 2 years and have always had good sex. He's only the 2nd guy I've been with ever. I'm 20. And I have no rhythm but he always takes control so it's not a big deal. These past two weeks have been really stressful for us due to a friends ex trying to start stuff saying he cheated on me because she's been trying to get me to break up with him because she's single now (which I know for a fact he would never and I know he didn't. I just thought that would help explain the stress on us) anyways, these past two weeks he hasn't been able to get off during sex. Idk if it's me or the stress. I've felt loose or like I have a weak pelvic floor so I have been doing kegels with Ben wa balls but it hasn't helped. And usually I could tighten up during sex and he could feel it and now I can't and when I try, he feels nothing. How he has been getting off the past two weeks and by him using his hand at the end of sex, on his is really bothering me.. I've tried talking to him about it but he says he doesn't know what it is either. And it's getting both of us frustrated. Any advice or tips on what it may be? 😔 I feel like I'm not doing good enough or I'm doing something wrong