LadyBug

Hi, I'm new here and have searched the forums for a similar topic but can't really find what I'm looking for so I hope I wasn't just missing it, here goes...

I have been with the same guy for 4 years now, on and off, and two weeks ago he broke up with me. Last week he stayed at my house for a five days and on the last day was complaining of a sore penis and that it was red and raw underneath the foreskin. He blamed it on rough sex. Today I spoke to him and he was saying it feels "tingly" and as if there could be an infection. I myself these past few days have also had this feeling. We both had chlamydia a year ago after he cheated on me with another girl so we know what it feels like. I know I haven't been with anyone else and he promises he hasn't either so I'm not sure how an infection could have got there. We both have appointments with the appropriate people next week but I'm really worried that if it is an STI he will blame me for it and never want to see me again. I can't stress to him enough that I'm not lying and really haven't been with anyone else but I don't think he will believe that if it does turn out to be an STI. So I guess my question is; what possibilities are there that it could be if we have both not been with anybody else? I really hope you can help me! Thanks in advance