Trackpad Mouse-buttons not working

At some moment, the right-click button of the 3-buttons under the trackpad of my Dell Precision M4600 stopped working. It doesn't register any clicks anymore. Also, the the left mouse button started to act weird. Sometimes, it starts registering right-clicks instead of left-clicks. Then I can reset it by logging off and on again to my user.

First I thought it might be because i sometime accidentally had some drops of water on the mouse-buttons. So i ordered a new set of buttons online and replaced the old ones. But the problem remains. The problem occurs everywhere, on desktop, taskbar, browser...

First, I could see in the Dell Touchpad icon, that the right-button was constantly registering being pushed or not registering anything at all. Now, after putting in a new set of buttons, that doesnt seem to be the case anymore, so it registers when i push the button, but still nothing happens (the right-click menu doesn't open for example). And sometimes it still registers as if the button is pushed constantly.

I have before already reformatted my computer and reinstalled the drivers to everything. That didn't help anything. The only thing that changed is that now, every time I restart my computer, the screen-graphic settings go completely bad as if it's set to 16-bit color. And then I have to make the screen reset the color settings to get it fixed.

I checked the Dell touchpad settings, and everything is set as it should be.

Anybody that might have an idea where the problem could be?

Thanks in advance