I have been EBF my 4 week old DS with the occasional expressed feed during the earlier weeks.
We really struggled at first with exceptionally painful feeds...He had a tongue tie that was missed at birth and privately separated at 2 weeks. I also received advice from the hospital feeding team mainly around latch for the tongue tie but also different positions etc.
The last week he has become quite fussy, screaming during and after feeds, arching his back, vomiting, hiccups constantly (had them frequently anyway), has been really snorty/sniffly since birth and latches on and off. I took him to the GP who diagnosed reflux and prescribed infant gaviscon.
I was giving it to him 6 times a day with water from a syringe but he hated it so then I tried a small amount of expressed milk from a bottle. He also seemed really constipated from it (would scream and grunt but then relax immediately after a bowel movement) so I then tried it 3 times a day instead.
He's still sick occasionally and still shows all of the above symptoms just maybe to a slightly lesser degree. His dirty nappies have reduced to only one a day now (but it's always a big one and the consistency is a lot thicker so maybe due to the gaviscon?) but has plenty of wet ones still.
My main issue now is that the fussiness has become unbearable in the last 24 hours. He has been feeding hourly since midnight, won't settle after a feed, latches on for around 2 minutes at most and then cries and fusses. He still takes the gaviscon in the bottle fine though 
He is definitely seems hungry as he roots and chews his hands but just won't feed properly. I think I might have an overactive/forceful letdown but I don't understand why feeding has gotten so much worse.
I've tried skin to skin, just feeding from one side in case it's the letdown, feeding from both, feeding standing up and nothing seems to work.
I'm so close to buying formula for him as in worried about him being hungry and/or not being able to express enough to feed him fully and him still being hungry.
If you've made it this far thank you for reading, I didn't expect it to be quite this long!
Has anyone got any suggestions? I've just cried all day and I can't carry on like this. Am I better off just giving up and buying formula?