Car alarm problem

[Apotex81]

So i bought an impreza 2008, no fob and one key.
For the first 2 weeks the car worked without a problem. One day i auto lock from inside and leave the vehicule the lock the car from outside.
Next day i i open the door and the alarm just goes crazy, no way to disengage it. Unlocking the door, cant start the car anymore. Unhooked the battery. Purchased a fob but cant program it because the alarm is always on.
Anyone please have a solution for this

 

[Ecmbuster]

Have a Technician scan the entire vehicle to capture the recorded faults. Have the faults repaired
Inspect the drivers door harness that may be damaged at the "A" pillar.
Fobs are programmed after the repairs are completed.