I'm trying to play minecraft, but my mouse won't let me harvest anything?

It goes all the way back to the double clicking problem. I've fiddled with the sensitivity numerous times but I'm still having the same problem. I have to really push down on my mouse to be able to drag stuff, mine on minecraft. Everything. Is there any way to fix this?

I'm assuming this is a desktop mouse, not a touchpad, with a few years on it. Over time stuff gets inside the mouse and can make it have some issues like your saying. You can /try/ opening it up and cleaning it, but its very hard to put it back together correctly (the buttons move a very short distance to click, so you have to put everything in perfectly). This leads to the moues not working at all after its put back together sometimes. So in short, I'd just buy a new one, they're only a few dollars on ebay.