oh, sympathy Star. I've had/going through this with ds too (really must get these babies together - they are clearly in sync anyway!)
my ds will eat bananas though. and cereal (cornflakes soaked in juice - leftover from him being dairy free).
and anythign with sugar in it. he had a ball over Christmas as we had a housefull, and he charmed loads of crap out of doting elder siblings/relatives.
it does sound as though teeth might be the issue - dd2 teethed all at once (although younger - about 10 months old), and whinged for weeks. she really was the most miserable baby ever, and I thought it was just her nature (she was clingy too, both before and after the teething), and then one day she yelled extra loud and wide, and I saw 6 new molars which had suddenly appeared! she went right off food while all that was going on...
my ds was off food in a big way (he is limited in what he eats now, but the quantity is ok) in October/November. He seemed mildly off-colour, but in hindsight I think he must have been quite poorly, poor boy. He ate barely a thing for weeks, and survived on extra feeds through the night
he has just started with his next round of teething, as tonight when brushing he teeth (which he loves), he was quite stroppy, and seemed sensitive/pulled away. so I expect he will be off his food again very soon.
anyway, I'm waffling. I have no idea what to do.