Paracetamol and ibuprofen will certainly help with the pain. But you shouldn't be tasting the ibuprofen! The sugar coating is so it gets to your stomach without damaging anything, and it only dissolves when it gets there, by which time it's gone SPLASH in the food that you've eaten to buffer it.
(to everyone: you must have eaten in the last two hours before you take ibuprofen or diclofenac, or it may cause a stomach bleed. A glass of milk with a tablet will do nicely.)
Erythromycin and penicillin are both broad-spectrum antibiotics, so it's not surprising you feel awful. Take a Tesco probiotic capsule every morning, or eat lots of bio-yoghurt, and it'll sort that out no problem. Also erythromycin can make your stomach turn over and over, so I avoid it wherever possible.
The other thing is - if your pain isn't sorted by the tablets, dissolve a lot of salt in a glass of warm water and gargle it all. It's a great painkiller, and it'll help disinfect your throat too. Antiseptic mouthwashes and tea tree oil dripped sparingly into warm water will also help disinfect.