Is it that darn fuel pump? Or... Help

Hi There..

I have a ford focus (2004) 4cyl 2.0 L.
One day, the car would stall only moments after the engine would turn. It would just shut as if fuel was ceased. I could however rev the engine and keep it running if I had my foot on the gas. After awhile, I tried again and it worked! Everything was normal, then it stalled after trying to start if up again. So this was intermittent at the time.

So, I swapped my fuel pump relay with the a/c one- and it fired right up! I'm thinking great, its just the relay and not the actual fuel pump. So went to the parts store, got a relay, and (me being me) wanted the new relay in the original fuel pump relay plug in the fuse box. As I was taking it out, a really really small piece of plastic chipped off of the plastic cover of the relay, and fell in one of the slots where you put the relay. How in the world?? I couldn't get it out. So I ended up putting the relay in anyway, and my car has the same problem originally (stalls), but now I have these check engine codes:
p0460 and p0463

I also noticed, its running really rough when I hold the gas now.
Could the plastic piece that fell into the relay be causing a strange short from my fuse box? Or, could it be my fuel pump this whole time? If its messed up because the plastic, Is finding a fuse box at a junkyard and replacing it feasible? Thanks for your help.

You may have gotten a bad relay put in the one that worked. If this doesn't work disconnect the battery ground. Unbolt the electrical center and inspect for corrosion or a broken wire on the bottom.

Anyone who had a similar problem- it was the valve cover gasket. Oil was leaking into where the spark plugs are. Changed the gasket and put some new plugs in. Good to go!