@AJLang - If I were in your shoes, I'd be phoning around my local podiatrists for an urgent appointment. We are very lucky locally to have a fabulous podiatrist with an interest in diabetic foot issues - she is a regular on our local DUK Group's speakers list. (Even better that she is a great speaker and has us all self examining (or not if you don't want to), as she talks us through what we should or should not be seeing or feeling.
But, I digress. Were a podiatrist to find you needed something he/she could not provide, they have direct access to GPs and other podiatry/foot services for urgent action.
Of course, the beauty of electronic prescriptions is if a podiatrist (or whomever) asked your GP for antibiotics, or whatever, it can be actioned straight to your nominated pharmacy.
Fingers crossed for you, but that isn't something to "sit on" over the weekend.