I'm at the end of my tether - my 16 week old son still feeds every 2 hours like clockwork during the night and I'm due back to full time shift work in three weeks. I also have two other young children and can't carry on like this or I'll make myself ill 
My DS is demand breast fed and feeds every 3 - 4 hours during the day. I put him down to bed at about half six and he'll wake at about 10pm for his next feed. He then feeds every two hours throughout the night until 7am when we get up.
I've tried dummies but he repeatedly spits it out or gags.
I've tried a bottle of formula at 10pm after which he might manage 3 hours but then wakes 2 hourly thereafter.
I've tried swaddling and not swaddling.
I've tried rocking but I end up just being awake for 10 extra minutes before he kicks off, crying to be fed.
I've tried feeding him every 2 hours during the day in the hope he'll stock up for the night but it didn't work.
Please, please help - I don't know what else to try and I'm really not happy with the idea of co-sleeping...
FWIW he has been diagnosed with a floppy larynx and mild hypotonia (low muscle tone) if that might have a bearing...