1999 Toyota Tacoma Engine missing badly

I recently moved to Kona HI. I picked up my truck yesterday and everything was running fine. Today, I drove to the store and when I got back, I decided to clean my battery terminals with baking soda and water. While doing this, I broke the copper connector attached to the wire that runs to my fuse box and attaches to the positive post. I was unable to find an exact match but found a suitable substitute. Now when I start my truck, it misses badly and will not rev past 4000 rpms. I recently replaced all wires and spark plugs and everything was good until today. Thanks in advance