WHY WON’T HE CUM?? Please help 😭

So my boyfriend and I have been together for 6 months but only recently started having sex. Before we had sex, I would give him blowjobs and he would cum. The night before we university ended for summer was the first time we had sex and he cummed straight away as soon as he penetrated. Then, due to summer, we were apart for 4 months. Our relationship is good and we made it through summer but now that we are back at university of course we are having sex again. But, even now when I give him blowjobs he cums but when he penetrates me he doesn’t cum as quickly or at all sometime. WHY????? I’m starting to feel really conscious about it because he said that his best friend told him that it’s normally a guy cums quicker when he penetrates a girl. Is it me that’s making him not cum when hyou penetrates? Can I do anything to help him?? Any suggestions please because I’m feeling so rubbish about myself rn. Thanks xx