Trust issues

Okay, so I'm going to rephrase this question because last time there was some rudeness going on and if you're going to judge you can leave. So I just need some advice, preferably from women who have been there.
So, I've been dating this guy for a year and a half. I recently found out he gave me chlamydia. I've also recently moved closer to him. Sex has not happened since I found out, and I've been trying to avoid it. He told me he wanted to work on our relationship and things have been good so far but of course I still don't trust him. I do want to trust him again but I'm not sure when I should be intimate with him again. Most of you will probably say whenever I feel comfortable with him again BUT there's a blurred line between not being comfortable and choosing to be petty to get back at him. So I'm not sure if I'm really not comfortable or if I'm really subconsciously being petty. My aunt was in a similar situation with her husband and her therapist told her she had to have sex with him in order to help they're relationship. I understand I'm not married but I do want to work it out. Any advice..no rudeness please.