What's up fellas'

My car is acting up unfortunately. I was having a little fun with another car down the road the other night. I took the car up to about 100-110, shifting around the 6,000-6,500 mark (car is minorly modded, only mods are air filter, HKS bov, and the free mods).

Once the hit the 100-110 mark, I decided to let off since I had a pretty decent gap ahead of the other car. Upon braking for the next intersection way head, my car started vibrating violently. My RPMs were hunting up and down sporadically and the needle was very, very low when I was at a complete stop. The car started to "put put put" (misfiring perhaps?) and was fixing to die at any moment. I had to keep the engine revved up with the gas pedal to keep it from dying. Once the light turn greened, I started to accelerate, but the entire car continued to shake/vibrate violently when I pushed down on the gas. I limped it home and the car died within a few seconds after parking it. I started it back up and the car seems to still be misfiring very badly, shakes roughly, and the exhaust is producing the "put put put" syndrome. I popped the hood and can see the valve cover vibrating pretty badly.

I would think it most likely is fouled spark plugs and or wires. My concern though is, in addition to the aforementioned syptoms, I hear a pretty loud slapping noise coming from the valve cover. It shouldn't be too severe I suppose?

The car has about 90,000 miles on it now. (Mobil 1 synthetic is used). I didn't bottom the car out or anything and the oil level seems okay. I'll check tomorrow for any severe leaks, etc.

Any input is greatly appreciated. I suppose I can try to limp it over to a service station, but I don't want to risk damaging the motor more (if any), is occuring to it.

Thanks for your all's time.