Oh dear, I know exactly how awful it must be to have to suffer ear pain from an eardrum infection because I have experienced it myself before!
Eardrum infections commonly result from having had a bad cold or flu as the same "bug" that caused the flu, tracks up the pressure tubes (Eustachian tubes) which lead to your eardrums.
I wonder what antibiotic you have been prescribed? The "bugs" which cause ear infections may sometimes be resistant to simple penicillin/amoxicillin which is what many family practitioners usually prescribe. I hope you're on Augmentin or Klacid because they are the best antibiotics for eardrum infections.
If your ears are still painful and blocked, there might be infected fluid or pus trapped behind your eardrums which may need to be drained to relieve the pain and improve your hearing. Draining the trapped fluid behind the infected eardrum may be done safely in clinic after applying some "magic" cream inside the ear to numb it so that this minor procedure may be performed comfortably.
You should definitely see an ENT specialist instead of heading down to the A&E because the ENT specialist has a microscope and a fantastic repertoire of refined specialised instruments with which to examine your ear under high magnification and to perform the eardrum drainage procedure if necessary.
There really is no advantage to continue waiting any longer if your ears haven't improved after 3 days of antibiotics. Please go get your ears carefully checked out by your friendly ENT specialist!