STI

Hi everyone,
I hope you can help me. I did something really bad and I hope you won't judge me. My boyfriend and I are trying to conceive, but we had such a huge fight two weeks ago, it doesn't matter what it was about, but I went out with a group of girlfriends that evening and met someone, and went home with him..We had safe sex, baaaat the condom broke! Now I have a lot of discharge that's different from normal and it itches really badly. I looked it up online a bit and came across Chlamydia info page and it seems like I have an STI!! I had sex with my boyfriend after that too and I'm terrified to tell him because I really don't want to lose him and I feel so guilty. What do you think I should do??

X B.