I also play by ear. I have been playing for about 5 years and I was in the same spot as you at one point. I was feeling stuck...like there wasnt anything else for me to play! I call it drummers block! Try taking a tom off of your set and take a couple cymbals away. This will make you figure out ways to do fills. You can also get some cd's to play along to. I don't know what kind of music you are into. I suggest Kirk Franklin. He has some really good songs to play along to with different beats and they aren't easy! You could also try Skillet, 12 stones, Switchfoot, and kutless (these are all christian bands). Theres also a praise and worship team at a church called Lakewood. They have many cd's. One that I really like is "LAKEWOOD LIVE". It has tons of great songs to play. If this doesn't work get some lessons! I use these things and it has helped me become a pretty good drummer. Good luck and god bless!
-Heather