Help help, installed kill switch

[Lenie]

My battery is in the trunk, had american auto wire install, their 10 guage wire went from my one wire alternator to the starter. I decided to install a big switch flaming river kill switch in the trunk, so what I did was disconnect and remove the 10 gage wire from the alternator to the starter and installed a 4 guage wire from the alternator straight back to the kill switch in the trunk to the battery side on the other side of the kill switch I connected the 0 gage wire from the starter. Here's my problem, before I began the switch the car started and ran perfect and now that I'm finished the car has a hard time starting, acts like it's flooded, runs really rough for a couple of seconds and dies. Any ideas? Here's a diagram I used for running the alternator wire to the kill switch in the trunk. Thanks