Did something stupid today

[gmcnoob]

Long story short is I had the battery and the alternator both disconnected for some electrical work and I reconnected the battery before the alternator. The wire for the alternator was touching the valve cover and there was lots of sparking there and also at the junction box on the firewall. Now I just have exterior lights and the courtesy/dome light, nothing else. Did I fry the fusible link at the junction box? Did I damage anything important? How do I fix this?