Shake, Rattle, and Stall....

I have an 01 3.5L w/135,000 miles. The other day, I started the car and the entire car shook like crazy, but managed to move back into the garage about 10 feet. I shut it off thinking it was just cold and old. I tried to start it a couple days later and it shook, rattled, and then stalled out. Tried to start it again and it wouldn't turn over. Later that day, I made sure the oil was full and tried again. The third try, it started and managed to stay running, but the engine was still shaking violently. I really would like to avoid paying to tow the car to the dealer to get charged $100 for a diagnosis. Any ideas would be greatly appreciated....Thank you

You could get a code scanner from Autozone.

I tried that and it told me engine misfire....quite vague