Nicky, keep talking and telling us about it on here.
You will get through this and your little one will get over this reflux. Your family won't suffer in the long term from the attention the little one needs from you right now and letting him cry for a min whilst you sort one of the other ones out isn't a crime.
Thinking awful thoughts about him doesn't make you a terrible human or mother. It simply makes you human....
I remember spying the corner of the worktop when I hadn't slept through a three week bout of teething by our son. I hated him and I just thought to myself if I knock my head of the corner there, I'll get some sleep....
I didn't! But it's what being driven to distraction does to a woman.
The little one isn't being naughty, he isn't doing this on purpose, he's not a moany child.....he's just a baby with a terrible pain. I would repeat this in your darkest moments again and again.
When I found myself growling to myself after being woke for the millionth time a night and the hate coming off me in waves, I'd almost meditate a prayer to myself en route to his room "God give me kindness, patience and compassion when dealing with this little soul".
Sorry, I didn't mean this to be so long.
If you are fraught, a visit to the docs may help you enormously. It did me - and a low dose of citalopram too!
I'm really thinking about you.