Jumped my car off improperly

This morning I jumped my car off and accidentally hooked the positive jumper cable to the negative terminal and the negative cable to the positive terminal.
Now my speedometer tachometer odometer stereo A/C power window controls brake lights backup lights and turn signals aren't working. I checked all the fuses I could found none were damaged that I could see. Bought a new battery put it in still those things don't work. I've talked with a few mechanics but they basically all tell me different things. A few said it was my ECM/ECU and others said it was relays or fusible links or fuses and I had one say if it was your ECU/ECM that my car wouldn't run at all. I do not know what to believe or think is wrong and I don't want to take it to a mechanic because I don't want the it is this then them charge me to fix it then it is still not fixed, now it is this or that plus the last mechanic I took it to misdiagnosed a different issues and I had ti fix the issue myself, which was ridiculous especially since I had all hand tools and did the job in the same time they charged me for them to do it. But they have all the specialty tool like lifts and impact wrenches, etc, etc.