Need help

So I have a 2003 Mustang Roush 4.6 V-8, my service engine soon light came on and I got the codes read at Auto Zone and come to find out I had misfires on 3/5 and also ignition malfunction. So I began to replace the spark plugs with new motorcraft plugs and attempted to use the old coil packs. I raised the fuel rail a bit on the forward end to get the coil packs out and a bit of fuel came out. I complete 1 side (drivers side) and it got dark so I put everything back together to finish the next day and started my car to move it and now it will not stay in idle it just dies and also have a lot of white smoke coming out of the exhaust. This is my first mustang and im at a loss and don't want to do any further damage...Need help