Second screen issues

So I changed my 1st priority screen's resolution(the one an application automatically puts the interface) it then went black, that's alright, I waited for the automatic revert after 15 seconds, before that 15 seconds had concluded, my computer crashed I turned my computer back on and if I tried to change it back, the interface for settings would be inaccessible. I am currently only able to unplug the 1st priority(and better) monitor then restart my computer to use the second screen by itself.