KA misfire making it shake real bad?

[240SETulsa]

I think its becuz one of the plugs is bad but idk. At idle it seems like its bogging down and it shakes back and forth a lot but at rpm above say 1500 it even out and seems fine although it does show signs of loss of power (the engine shaking or rocking goes away but power loss seems so). It started yesterday and I couldn't figure out what was wrong and upon returning to my car 4 hours later it started up and ran fine.

Today it started up fine and when I drove it to work there weren't any issues. But when I drove to lunch and came back to my car it did it all over again. I pulled the spark wires from the distributor one at a time to isolate which cylinder the problem was in. Its number 3. Dont know if its the wire or the plug or if I am heading in the right direction...