Itchy vulva and cuts/sores - STI?

Brief history - I was a virgin before meeting my boyfriend, so obviously no history of sexually transmitted diseases. Hadn't done anything sexual before meeting him. We used condoms when we first met, then I went on the coil to treat my heavy periods, so we agreed to condomless. Though he's had three other partners, he's only had unprotected intercourse with one other girl (3 year relationship) & has been tested since. I've had constant UTIs in recent months and am constantly on antibiotics to treat them. I've been referred to a urologist for treatment. I also have to wear panty liners every day 'cos I'm still spotting on the coil.

Got another UTI about three weeks ago, but this time have had itching on and off since. The itching seems to be getting worse and worse and whilst in the shower tonight I investigated there are two things which look like raised bumps on my vulva and that's exactly where the itching is.

I really don't know what to do! I've considered that it might be a STI, but obviously don't want to go around accusing my boyfriend (in my heart of hearts, I really don't think he's cheated on me.) But equally I wonder if he might have something from the past that he doesn't know about. Even though he's only had unprotected intercourse with one other girl, I think he may have done oral with the others. On the other hand, I'm thinking this instead might be something to do with my UTI issues, or just be slight abrasions from wearing pads all the time in the recent heat.

Really don't know what to do and would love some advice!

my first instinct tells me the coil is causing ur problems, plus ur stressed to the max it would make the skin down there extra thin and very easy to tear, plus u can get thrush which is itchy from being very stressed. or diet can also make things act up.. id go and insist doc arranges to remove coil and try a dif method of contraception and see if ur problems down there go back to normal, and if they do, then u know it was def the coil. if problems still persist after a few weeks, say, six weeks time then get a swap tested for any minor std's which u prob haven't got. hope u get to the bottom of the problem

Thanks for the responses

The itchiness has now stopped! I'm really reluctant to ask for the coil removed though because it's the only contraceptive I've ever had that I've not reacted horribly to (I have terrible side-effects on the pill). Also, if I stop it my periods will return and the heaviness of them causes me to be pretty much unable to function for 10 days of every month.