I suspect he has enlarged tonsils too sweetie. Lots of milk shakes, fruit jelly, things that are really easy and dissolvable.
My DS had a double chest and throat infection a while ago and he just stopped eating, period, initially wouldn't even have a milk shake...it's SO worrying. We gave him a LOT of fruit juice icy poles (pops, I think others call them) as he would drink them and the ice must have helped his throat (he was also on mega antibiotics etc), as soon as he started to feel well the eating came back.
I would visit the doctor honey, hope your LO feels better soon
xx