Hello. Trust me, you really don't need to worry about it. All those things that you are describing sounds completely normal. Your penis will be very sensitive two days afterward, sometimes even more. I remember my ugliest experience - I just went for a short walk that second day, and almost turned back again, it was so annoying. Also, it was swelling a swell. I don't think that this is one of the major circumcision complications. I believe that this is normal, at least, it happened to me and it just vanished. You will be OK, but still, control it.
If your circumcision is loose I would expect the area right behind the head will be covered by it most of the time too, but that would not be any more often than mine is.
I might suggest the rubbing alcohol trick I used, and masturbating dry like I did, while holding it tightly back and making sure you rub the sensitive area as much as possible. There's no rule that you can't have a lot of fun and pleasure while desensitizing those areas and I'm quite sure that touching/rubbing the sensitive area enough will desensitize it.
If I were going to get circumcised I would want it high and tight to preserve as much inner skin as possible. The inner skin is stretch sensitive and adds a lot to YOUR pleasure during intercourse. I would also NOT want the skin bunching up behind the head when flaccid.
try applying LOX 2% about 20 minutes before intercourse and wash it off just before you go for it. it will make ur penis head a bit numb and give you a longer performance.
A scientific article particularly relevant to this would be "Removal of Foreskin Remnants in Circumcised Adults for Treatment of Premature Ejaculation - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3130485/ It seems partial removal of foreskin can worsen premature ejaculation, while full removal can help resolve the issue.