What is this sudden itchy rash on my feet

[Evie2016]

I've come up with this rash all over my feet. It looks like lots of little raised bumps all over the tops of my feet. They do not have pus in them. Though you can feel them if you rub over my feet. Lots of small bumps all over my feet including my toes and sides. The are extremely itchy and they kinda of hurt. So much that is uncomfortable to wear shoes. It has been quite hot lately so thought it might have been a heat rash though it appears to be getting worse not better disputed trying to keep my feet cool.

I have tried hydrocortisol cream with steroid, cold cloth with water, antihistamines, anti fungal cream, cold fan on it, iceThough nothing helps. It's so itchy, and if I itch it it gets worse it also appears to be a little swollen.

I have changed anything thing that I do normally., though the day it appeared I was wearing shoes not sandals. Please help the itch is driving me crazy that it's difficult to sleep and go to work