Alternator problems?

Hello,

So far in the last two days I've gone through two batteries. Two days ago I was trouble shooting a seperate issue, I had swapped out the fuse box located next to the battery, when I swapped that out my seperate issue continued so we knew our problem was the body control module. Well since we put our old fuse box back in we've been going through batteries like water. There's "fizzing" happening on the positive terminal of the battery and just moments ago after my wife needed a jump start the rpm's were going all over the place and randomly the check engine light and other lights were flashing on and off. I wasn't sure if we just need a new alternator or if we messed something up with the fuse box. It seems like an alternator issue but the timing of all of this revolves around the fuse box.

Any suggestions?

Thanks and God bless