Maybe he's sleeping too much during the day time? He should only get 2 naps which are 2 hours each so a total of 4 hours maximum in the daytime (usually one AM and one PM nap). Your baby needs a schedule for eating, playing and napping.
Here's an example:
8am breakfast
10am nap
12 pm lunch
2 pm nap
4 pm snack
5-6 pm dinner
8pm down for the night
If you stick with the schedule, in a week or so, he should follow it as well. You must be consistent with when you feed him. Whether or not he naps, it won't matter. As long as you try to get him on a schedule of being put down for nap and letting him rest during those two hours. Once you wake him, feed him. Then for the rest of the time, he can play until it's nap time. If he starts falling asleep during his wake time, do your very best to wake him up. Just make sure he's awake when he should be and not falling asleep. Also, no TV or too many things with flashing lights/music. Sometimes toys are too stimulating that it makes it hard for little ones to go down for a nap or for the night.
If he is teething, try Motrin for the pain at night. During the day, give him teething drops or baby orajel. We use Gentle Naturals Teething Drops for our baby. It works, but use it every two hours until the teething is over or as recommended on the label.
Hope everything works out for you. Good luck!