Need help with fuse #9

I own a 2000 e46. During it's first 10 years when i hit a hard bump my display would indicate that the brake lights were burnt out. First time I replaced them and nothing happened. After further investigation I found out fuse 9 was blown. I replaced the fuse 5 times during the first 10 years, and everytime after a hard bump. In the last 4 years it has gotten worse and now, after I turn the ignition to the 1st stage it blows the fuse. Anybody knows what it can be? i've bought a new brake light switch and it did not solve anything.

i would appreciate any help anyone can offer. maybe someone in the forum has experienced something similar.

Thanks: