okay, last saturday I drove my 1989 750IL to a window tinting place to have it tinted to 5%
I was told to come back Monday as the tinter was gone for the day, so I went back to my car, and it would not start (I was out of the car maybe 2 minutes)

I checked the fuses
I replaced the battery
the starter and solenoid were replaced less than a year ago

I called AAA
they sent a flatbed
the tow truck driver insisted that he could jump if from his truck, that my car just needed a bigger boost
I told him I replaced the battery
He said it just needed a boost
He jumped it, nothing happened
so he towed it home
I went to look at it the next night and the battery was dead and the flashers
kept coming on, so I hooked a charger to it and let it sit over night
the next day, I went to look at the car with a mechanic friend of mine, he put the key in the ignition and the alarm went off, he shut the drivers side door and it shut off
I opened the door turned the key the alarm went off again, so I shut the door
I opened the door again, and the alarm went off
this time we had to shut the passenger side door to get it to shut off
I removed the fuse for the horn and tried it again and the alarm (no siren, just the horn and lights and flashers) went off again.

I was looking up the alarm in the owners manual and saw that you aren't supposed to jump the car from another running vehicle because it could cause electrical system failure, my mechanic friend says that the flatbed the tow company used was the equivlent of two cars trying to jump it.

I want to know if this could be anything other than frying my electrical system.

He did not fry your electrical system. That is why you have fuses and relays. The system they use is still 12 volts for jumping vehicles. The siren is not the horn. It also has nothing to do with the horn.

why did my horn continue to go off along with the lights and flashers
after I removed the fuse for the horn?

Because the horn and the alarm siren are different devices...

I got that
but I know the difference between a siren and a horn
unless they are two diferent names for the same sound.

Turns out the some wires got crossed, and that's why the alarm was going off,
and it was the alarm. I DO NOT have a siren, I have a horn, that is also why the horn continued to go off after I removed the fuse.
When I fixed the wires it stopped.
Now to get it to run again...