L.A.
First, I bet it's SO HARD to be devoting 90% of your time to your son and have him act like he is getting 3% of the attention. Kids sure aren't fair! My son went through this in his 4's, so I really do think that it's a normal phase of growing up even though it's NOT something you want kids to be doing.
My suggestion is instead of rewards, punishments, timeouts and such teach him what he should be doing and saying. A reward is teaching that he does something for an external motivation. Having him well behaved without giving him a star (or whatever) is teaching him that he does what he should because that is what he should be doing.
Timeouts and punishments are showing him that this is not what he should be doing. But I say that moms should go a step farther and focus on the reason they chose to do a timeout. For example, don't timeout because he swears. Instead tell him what he needs to be saying. Show him how to talk politely. Have your follow through be the desired actions and words instead of a timeout. (A timeout can be a way out of doing something.)
Another thing that may help is to let your son know that you understand what he's telling you. (though it's in a very wrong way!) For some kids, once they know that a parent hears them, they calm back down quite quickly. Mom: "You're SO MAD about this!!". Kid thinks "yeah. That's exactly it. You know where I'm coming from. I'm heard." -- then -- you continue with teaching what you want to be happening. "You're so mad, but we need to do this because of such and such. We can do that afterwards." (hope that makes sense)
Hang in there. Keep teaching him how to react and what to say to get his point across in a polite manner. Then teach him what should be happening and why. (though I don't think at 3 he will be able to get much of the higher reasoning. He's very here and now in his thinking at this age.) Punishments are teaching him that you don't like it, but being a role model and walking him through something is teaching him what he needs to do and how he needs to say it.
Hang in there! It does pass ... eventually. If you can use humor, that's a great thing too, but it can be hard to do when you're frustrated. Humor is great a disarming a situation so that you can continue and get your goal accomplished.