Pontiac Grand Am Problems.?

I have a 1998 Pontiac Grand Am with 126,000 miles the car has never had any major problems a few weeks ago it shut off while I was merging into a turn lane and when I finally got the car started back it was running horrible and the check engine light is flashing. The engine is shaking really bad and you can here something jingling around like metal rattling. The car has plenty of oil and was always serviced on time. When I had the car checked at Autozone they gave me two codes. PO107 and PO300. I have replaced the spark plugs and I also ran a can of sea foam through the injector system and neither of these things helped at all if anyone has any ideas please let me know. Thanks.