It could be reflux, the behaviours sound a bit like my DD who has silent reflux. How does your LO do with sleeping? Does he show any signs of discomfort during naps/night sleep?
You could talk it over with your doctor or health visitor or equivalent depending on your location.
It is the fussing and arching and crying that sound a bit like reflux to me, have you had a look at the symptoms of reflux post to see if anything else sounds familiar?
Alternatively, it could just be that your LO likes to take a break in his feeds, several of my friends' babies are similar with that. Why does it make EASY difficult to have this? I've forgotten what an A time is for a baby of your LOs age, but there should be time to fit in the feed even if it takes 45 mins/1 hour in total. I may have misunderstood you though. Also how often are you feeding and how old is your LO?