chlamydia in relationships

My girlfriend went to the doctor yesterday to go over her results from her pap test that she had back in December. Her reason for doing so is because I had symptoms, went to get tested and was positive for chlamydia. She had been tested for sti's in her pap also because her doctor was suspicious of a lesion I had on my frenulum after a tear in one instance that bled during sex. I had this checked at planned parenthood and was told it was not sti related but could help infection take place. My girlfriend was negative for all infections in December, my symptoms came in January. We've been together 6 months and I have had no sexual contact with anybody since, but had a month before we met. She swears she hasn't cheated either, hence her revisit to the doctors and her suspicion and doubt for me. I used a vibrator and lube I found whilst cleaning our room one day and wondered if that could be of suspicion. Or Is it possible I carried this from sexual activities with the girl I met a month before my partner? Only to get symptoms now? And if so is it possible my girlfriend just hadn't been infected by me until this point.

She got a test done at her revisit and we are waiting for the results but I can't see her not having it if I do. I've been treated and she has the meds now too.

I'm being accused of cheating by her, her friends and her doctor and I'm becoming depressed.
It's putting a huge strain on the relationship and I'm desperate for an answer. I do believe her saying she hadn't cheated because she's terrible at telling lies and she cares so much for me.

Like I said I've never touched anybody since I've been with her let alone after December, just the toy. then I get the symptoms mid January. I know the relationship part is up to us but this has hurt, confused and frustrated me.