Abcesses are really quite easy to diagnose for doctors, and very definitely one of those " a stitch in time" type things. If (when) they burst, they are seriously bad A&E news. If nothing else, it's a good idea to see your GP just to set your mind at rest.
If you were on Pethidine (aaahh, I remember that dreamy floating feeling !!
Did you need a plane, or did you fly home yourself ?
) ) then your condition was serious, and you are not being too paranoid, just reasonably cautious.
I've been through the whole "we'll make an appointment/we'll change things in a month or so" rigmarole that passes for treatment in the UK, and although I am quite scathing about
it, I have found that it doesn't pay to second guess what the doctor will do or say. There have been times when I have been pleasantly surprised, and by gum, was I glad I'd gone !
But of course, it is always hard to go full of hope, and sometimes get disappointed; I think of it as nothing ventured, nothing gained.
Are you watching your diet ? That's something that can sometimes pay off bigtime, without any need for professional medical guidance. (In this instance, NHS usually means No Help Supplied.)
Best of luck, whatever you do !