Did you do the bonus quest series?
Did you do heroics?
Did you do flashpoints?
Did you do space missions?
Did you do PvP?
Most of it is optional, but it is easy to stay above the required level for planets.
Look this is going to be my 3rd charator! The only gap i have issues with is going to quesh.. Every other planet, you can keep in range just by doing the odd warfront and space missions.
I don't do flash points, they take too long to get going, don't give anything in return at all.
Leveling is just too fast, to fanny around with instances and heroics.