i had some sleep issues with DS like this around the 2 month age.
My paed advised me to get him into a 2 hour sleep cycle.

pretty much every 2 hrs put him to bed. EVERY 2 hrs.
SO if he wakes at 6am - put him to be at 8am - if he wakes at 9.20am - put him to bed at 10am, if he wakes at 10.40am - put him to bed at 12midday and so on.

I started doing this and within a day or 2 he was an angel! sleeping beautiful regular cycles and back through the night.!!

worth a try