trackpad button not clicking, too sensitive

It has slowly become worse - the button below the trackpad won't click down depending on what the computer is on (my lap or desk. oddly it still works when the computer is on my coffee table). The corners will click, but not the center. It does read clicking though - it has become too sensitive, to the point that sometimes scrolling or more often have my wrists or palms touch the edge of the computer (but not the button) results in a perceived click. It's gotten annoying because it means sometimes while i'm typing it will have "clicked" without me realizing it, erasing text or something of the like. I'm not sure if the plastic itself has warped or if that could somehow cause sensitivity to clicking on other parts of the computer.

I am not sure if it is related, but part of the casing of the battery won't lay flat anymore, and so the battery bulges a bit from its section. I say this because part of the battery is below the trackpad section, and I'm wondering if this could contribute to the click sensitivity (bringing the sensor closer to the plastic casing or something).

What's the problem here? Is there something I could replace to make this go away?

• under trackpad preferences, there does not appear to be a setting for the sensitivity of the button itself, just the scrolling speed and double-click speed. clicking for the trackpad is off.
• my current trackpad settings are: tracking speed (5/10), double-click speed (5/10), scrolling speed (5/11), checked boxes: use two fingers to scroll, allow horizontal scrolling, zoom while holding ^control, secondary clicks, ignore accidental input, and ignore when mouse is present.