I'm not a doctor, but I think you need to see one. It sounds like you have an infection, but probably not yeast. I expect there is a simple medical solution, and the sooner you get the cure started the better.

You could try (this works for many vaginal & other infections too) having a long hot bath with plenty of apple cider vinegar (not just regular vinegar it may help but) & flush it or wash it through/over/into the itchy/infected area. I have found this works really well, sometimes it takes affect immediately other times it takes a few days. I also tend to find that it works best if I shower & wash first so that the water & vinegar are soap free & cleaner & if I stay for a good while. I generally take a book & a cuppa along with me & wash/flush the area intermittently for a half hour or so. It's also quite relaxing.