I am at my wit's end here. DS2 is 16 weeks, very sunny and cheerful when I am not trying to feed him. He latched on immediately after birth with no problems and fed well at once, gained weight v. rapidly etc. But two-three weeks ago (so at about 13 weeks) he started to latch hungrily at feed time but then almost immediately comes off screaming. We repeat this over and over again for a nerve-shredding 30-40 minutes as he gets more and more hysterical before he finally settles to the feed. He appears to be in pain. It doesn't happen with every single feed, but about 2/3 of them - say 3 of the 5 day time feeds on average.
Possibly relevant facts: he has had one bottle a day since birth, but it happens with the bottle too, though not quite as often (about 50% of the time) and with the bottle once he gets going he is OK, the problem is just at the beginning. So for whatever reason the bottle seems to be a bit easier for him.
I can I think see two 'tooth buds' on his middle lower gum, though I'm doubting myself a bit as it seems very early? If they are teeth, they haven't broken the surface yet. Could this all be a teething problem? He is chewing his fists and anything else he can get desperately all the time, even straight after a large feed.
When he is distressed as I try to feed him, either a dummy or chewing on my finger calm him down most quickly. I have tried teething gel and it seems to help slightly - he latches on and goes for a bit longer - but doesn't solve the problem.
It is just so awful, I feel I am torturing him every time, it is totally nerve-shredding. He has wet/dirty nappies so he is definitely getting a reasonable amount but I am worried that he may be underfeeding a bit cumulatively.
He did suffer quite badly with colic from 4-12 weeks but it faded from around 10 weeks on cue and there was a lovely fortnight-ish before this new problem appeared.
Sorry for the epic essay but would be so grateful for any help or suggestions. Just called breastfeeding helpline who suggested reflux but I thought that caused pain during/after a feed not at the beginning? And he never really throws up, just small posseting sometimes in a totally normal way.