Is there anything i can get from the grocery store or drug store for my rash until i can see a doctor?

Maybe: A painful rash could be due to infection, allergy, insect sting or bite, trauma, burn, and many other possibilities including a reaction to creams, salves, or lotions that you may have already tried. What you need more than anything is an accurate diagnosis. Anything you try from the store will be a gamble and may delay your ultimate treatment. Please see you doctor!