Help!!!

I am 19 yo, and I lost virginity to my boyfriend in June. Since June we’ve been having sex once a week, sometimes 2 or 3 times. I have never had a problem with dryness.

In August I had to take plan B since condom broke. After that, my cycle did change, but not that much.

At the end of September my sex drive began to fall... I am under big stress due to university, new friends, new life, new everything, but it is very hard for me to see that I have basically no interest in sex. Even if I get horny it doesn’t really last. Today we were having sex (after nice foreplay, my boyfriend really tries hard to get me in the mood) and after like 5 minutes I started to get dry... I was still in the mood, but it was like my body was against sex. We tried to continue but it was very painful (burning sensation) so we stopped... 😫😫😫 Will things get better? Is there anything I can do? Did anyone had the same problem? Please help, I am desperate