Tough problem. How do you break free from yourself? The bottom line is you have to feel your fills differently. How do you do that? Like Todd said, listening to a different set of music is a great suggestion. For now, recognizing the issue is a great step forward. Solving a problem first requires recognizing the problem. I have a few suggestions for you to consider.
You could try to "outlaw" those fills in your head for a while. Don't allow yourself to play them. You know what they are, they are super comfortable and flow out easily, but no, you're not allowed to play them! If you can't think of a suitable replacement right away, take baby steps and just keep time right through the space. You have to re-program your fill tendencies. Imagine a fill that is completely opposite of what you would normally play as you play through a space, but don't play it yet, just imagine it. This will create a musical tension inside you that hopefully spawns other ideas. If you create enough "good" tension, something will have to flow out eventually. By restricting what you are "allowed" to play, this should stimulate some kind of rebellious thoughts that hopefully will spill over.
Another thing you can do is try playing your same fills, but re-orchestrate them. Meaning instead of starting on the high tom and descending (for instance), start on the middle tom, then go to your closed hi hat, than maybe back to the snare, just to change it up. Hopefully this should stimulate new ways to approach your fills.
Another suggestion: Delay where you start the fill by a beat, a half a beat, 3 beats...your choice. You can play your same stuff, but you will have to rethink it a bit to fit in a shorter space. This will force you to think of something a little different.
I recommend trying to think of something polar opposite of what you would normally do, just to move you away from your default line of thought. You need to use your imagination and try and feel it differently. If you can't feel it differently yet, omit the fill and just keep time for now, because you're not allowed to play your usual fills. When you actually feel something different, only then should you try playing it. Force yourself to come up with something different for now. You need to push yourself out of this rut. It's all in your ideas. Nearly all musical issues start in the head first. Change your ideas, change your playing.