My touchpad on my laptop will not let me select anything right.

I was walking up the stairs and I had the laptop in my hands but I also had a book on top of it and the book kept pressing buttons when I took the book off, everything was wrong with my computer. I found out the sticky keys were on and they were making my buttons beep and I had to hold the buttons down for a long time before I could type. I fixed that, however, my touchpad still won't let me select things right. Everytime I go to select something it selects everything from where the cursor is to the point where I clicked and it won't let me deselect it.