It's quite some time since I went through this for the first time... but I remember it well. Is your last feed at about 10/11pm?
At first we upped his milk... Making up more normal formula than I expected him to want each feed... if he left half an ounce or so at least I knew he was satisfied. Unfortunately I had complications post birth that dried up my milk so formula was my only choice... was gutted but that's another story.
If he downed the lot I tried him with some more... an antenatal friend of mine whos little one was the same age used to drink about 16oz before bed time (7/8pm ish)and slept through a dream all night! Her HV didn't like that at all... but it was what her DD wanted
We started weaning DS1 when his normal happy routine (as set more or less by himself) went completely to pot both during the day and night. He was very grisly all the time and wouldn't settle at all... naps went totally all over the place. This was a bit early at 5 months or so... we started with baby rice then pear puree and have never looked back.
DS has also suffered V badly with all teeth coming through... you name it I've tried it. His teething started at about 3 to 4 months... although it was many months before any teeth actually broke through... then the front 8 came through together!
The best teething gel we found is Dentinox [http://www.dentinox.co.uk/TeethingGel.htm] as is suitable for little-uns under 6 months and has a neutral taste. We found the best way to apply it was in the bristles of the latex finger tooth brushes and let him 'chew' on my finger for relief [http://www.thebabycatalogue.com/prodinfo.asp?number=BDE034]
I have plenty of non medicine teething suggestions if you're interested
Being cold is sometimes a factor... going through that again over the past few weeks and DS is now just past 2ys!
Stick with your gut instinct... remember you know your child better than anyone and what suits one doesn't necessarily suit another