Troubles with security system

I have an Infiniti G20 Sport and the security system is acting screwy....

first it started with the lights would flash but it wouldn't make a noise when i locked/unlocked the doors.

then my horn stopped working at all.

then the remote stopped working on the doors, even with new batteries.

now if use the key to unlock the driver's side door the lights start flashing and won't stop until i unlock the passenger side door with the key. sometimes the lights will do this with no one in the car or parked without opening any doors.

also the doors will lock by themselves and you can hear the clicking noise from it trying to lock over and over and over. sometimes the doors will keep locking/unlocking but usually it's just locking.

where is the alarm so i can try and disable it?? if i do that will my horn work again?