The teething gel is a great suggestion, I try Lily without it first and if she won't take the bottle then I put the gel on and try in about 10 mins. I also use cold teethings rings that I put in the fridge - I have a good one by Nuby shaped like keys which fit in her mouth well, although she needs me to help hold it in place.
Lily is 4 mths and has been teething on and off for about 2 weeks, so its certainly not too young for your LO. Silly me, I wasn't expecting teething and didn't click that was what was bothering her until some more experienced mum's pointed it out!