What activities are you playing in order to raise your power level?
From 900 PL on, you need to do the newly active challenges to get powerful rewards. Normal drops won't help you here.
Challenges include (but not limited to): Weekly flashpoint, 3 strikes with subclass matching the weekly burn, 5 PvP Matches in each playlist (core or rotational), Gambit prime, ... You find the challenges on the director.
I've done everything other than raids and i did it all with friends (who despite doing the exact same thing under the same conditions and progress), i have yet to get anything above power level 900