clickpad and bottom of keyboard on early 2008 white plastic macbook--need help!

I have a white macbook, bought early 2008 so I think this was before unibody. My mouse button has been acting funny (simply does not click or punch down, but kind of "mushes", which does work to click--most of the time). Also, if I tap the keyboard on either side of the trackpad (basically anywhere in the bottom 1/3 of the keyboard) it clicks on whatever I'm doing. So I get involuntary cursor movements, accidentally shut down programs--it's a bit of a nightmare. It seems like something down there has slipped out of place, or something... Even resting my wrists on that area to type is moving the cursor all around. Advice? Anything I'm missing? Have had no other hardware problems other than the fan was replaced like 6 months ago. But this problem has been going on for a while, but only recently became seriously bad. Even just typing this, I had to do cmd+z several times because it double clicked on the paragraph and deleted everything.