Yeast infection?

Im about a week late for my period but i dont know if that has anything to do with this, for about 2 weeks now ive been insanely itchy down there but if i went to itch it its extremely painful... i was wearing thongs almost everyday over the summer and thought that may have caused some irritation so started wearing large knickers every single day. Thats not changed anything.

Also, ive been getting crazy amounts of discharge, been cleaning down there atleast twice a day, and its like a thick paste- theres no smell to it, its just disgusting to see. Could it be a yeast infection?

I panicked and got sent a Chlamydia test which i am waiting on results for but since spending even longer with these symptoms im wondering if it is actually a yeast infection

Ive read some symtoms of yeast infections are bad blood sugar levels, i am diabetic, and also the use of antibiotics, i have just finished a course of penicillin.

Any ideas?