I'VE HAD ITCHY ARMPITS FOR THE LAST MONTH, NO EXCESSIVE SWEATING,, DOVE SOAP AND SHOWER AND WASH SOAP OFF COMPLETELY,

It could be a mild case of Jock Itch. Sometimes it's possible to get it from using a dirty towel to dry off; borrowing someone else's towel or T-shirt; using someone else's soap or shower sponge.

While this could be all it is, you may also be reacting to a new product you've recently purchased. Try using a soap or deoderant you're used to rather than your new one (if this is this case) and see what the effect is.

Otherwise, make an appointment with your doctor to see what is really going on.