You are basically making a homemade Excedrin (acetaminophen + aspirin + caffeine). Stimulants cause your body to metabolize the pain reliever more quickly.
As for if you're ruining your liver, I can't say, other than you should probably go see you doctor and ask for a blood panel/ liver function test. Even if your liver values are normal, you'll know for sure, and have a baseline to compare future tests against. Plus your doctor may have some thoughts on why you're having a headache everyday.
For me it turned out that while i had acceptable blood pressure, it was high "for me", and a beta blocker took care of the most frequent headaches. But we didn't figure that out until we had ruled out a whole bunch of other things.
It was a frustrating journey to be sure. I wish you luck in yours.