Sex and itching

My ex and I broke up for a little bit. We were having sex during the break up but then we stopped. Now we’re talking about getting back together and of course having sex. I knew he had sex with two other girls but he said he wore a condom. We have been having sex ALOT. I shaved and got a little bit of razor burn and after that I have been really itchy and kind of swollen (I’m assuming is from us having so much sex) but why am I itching so much?! That’s literally the only symptom I’m having. I think maybe a yeast infection? But it’s only itching. I do plan on getting an std test since he did sleep with someone new. But in the mean time; tell me if this is normal.

DON’T come at me for having sex with him. We have kids together and I didn’t want a new body.

Edit. He does have facial hair. Could it be rubbing me raw or something?? I’m hoping it’s just a yeast infection. I am prone to getting them more often. But I’m not having any discharge.

Also. If I’m having symptoms of an STD or STI, would he be?! He says some STDs can take years to give symptoms.. it’s been about 3 weeks since he slept with someone and we just started having sex again about 3-4 days ago. He says symptoms wouldn’t be showing this fast.