What Causes Itching And Redness On Vaginal Lips?

Hi.
I think I might have thrush and I am a bit worried that it is something more....

I think I have thrush because
o I am quite itchy, erm, down there
o There is like a moist, powdery layer over my labia, looks like white loo role filaments or something but it comes off easily with a baby wipe.
o because I have been itching a lot, there are small patches on the outer lips that are pinker than the rest and quite itchy and sore
o There is no discharge that isn't normal, no odour either...

But, I kind of had sex with a guy in November, well it wasn't really sex, because it was my first time, it really hurt so there was only penetration for around 2 minutes in total spread over about 1 and a half hours. We used a condom, but took it off when we thought we'd finished trying but we tried twice more for about 10 seconds each.

I'm worried the itching and that may be something more than thrush, though I had been itching before november, quite a lot....

Please help, I would really appreciate it.