I understand what you're experiencing because I'm in the same situation as you. However, it seems that your condition causes more symptoms than mine. I get redness, itching, swelling, burning and discharge, and fortunately I don't experience blisters and sores. I took oral tablets, tried prescription ointment but nothing really helped. Yesterday the pharmacist gave me a topical cream called Fugacil. I'm still not sure whether it works 100% but admittedly my swelling and itching reduce so much after several applications. Just suggest it. You can see your GP and ask them for advice. Hope you get well soon.
That's extreme and not common for yeast infections. You sound like you also may have more going on. A rash like contact dermatitis or yes, a different fungal issue than yeast. You need to go back to your doctor about the sores that are spreading. Are you sexually active?