Overexcersing

I know overexcersing is bad for you, especially if you're not even close to being an athlete.  I'm never gonna be a marathon runner.  I'm never going to be an olympic weight lifter or a body builder.  I'm also never gonna be a fitness model...or any kind o' model!  Why?  I don't wanna to any of that. 

Now... I still can't seem to stop excersing for two hours a day.  It's gone down from 2 hours TWICE  day in the past few weeks.  Before that, it was 2 hours THREE times a day.  Meaning, I'm doin' good...  But not good enough.  I have to get it down to an hour a day and I'll be happy.

But I can't do it.  I just can't seem to do it.  Short of asking the gym staff to revoke my privileges and lock me out of the facility, what can I do?  Anyone have any advice?