Definitely don't be running it around at high RPM. Be methodical, simple to complex. Is a spark happening at all the plugs? Do you have any damaged plug wires or cap. How long were you running you controller before it started to run crappy? When is the last time you changed you fuel filter, is your fuel pump putting out. Trouble shooting can be a pain in the butt, if you are methodical, you don't end up going around in circles
Good luck