I have been following a lot of threads regarding 4 month sleep regression and my husband and I are looking for any advice regarding our situation 
From birth he has been a great sleeper at night and terrible for naps in the day (not an issue - it's improving). He sleeps in his own room (has done since 6 weeks) has a dummy, muslin cloth, music playing. This is the same for both daytime naps and night time. He has had the same nighttime routine since the get-go; wind down from 6pm, bath, pyjamas, story, bottle, dim lights, then put into grobag and left to fall asleep (which he does) no talking during the last half of the routine etc.
This was all working in our favour and he was sleeping through the night from very early on. Even he did wake from hunger, he would take a bottle and go back to sleep. Daytime naps he fought but i could deal with them a-lot better on a healthy amount of night sleep!
Now hit 14 weeks and he began waking every 2 hours after bedtime, we tried putting his dummy back in and shushing him. Which worked 50% of the time. The times he won't be settled he needs a bottle and will down a 6oz.
He then has nights where he will wake every 2 hours to midnight and then sleep through to 6. Or like last night woke 4 times and is having his second bottle of the night 
He was last weighed 3 weeks ago and was 15lb 1oz and has 30oz milk normally (6am, 9am, 12pm, 3pm, 6pm)
We are just so confused, he must be hungry otherwise wouldn't finish the 6oz bottle, and is calm and left to fall asleep after. Should we up the amount or frequency we are giving them? Or is this all the regression and we are feeding him unnecessarily? I has always been a hungry boy, sometimes not reaching 3 hours between feeds.
I feel so bad, he is constantly tired and grouchy as he is never able to catch up on lost sleep. Any hep or reassurance would be greatly appreciated