My Maytag Dryer won't stop stopping!!! :mad:

First it would stop 1/2 through the cycle, now it won't start unless I turn the dial to "cool down". Then it will only run for 2 - 5 minutes and shut down, before the dial reaches off.

I've cleaned the vent and lint catcher, no issue. I'm not sure what the problem is and don't want to waste money and time replacing parts I don't need. Any ideas? :)

Thanks in advance for your help!!!