With some dogs, violence will only get you more violence. You will not fix this issue by beating an already aggressive dog like this. It hasn't worked over dozens of times and I doubt what you are doing will work better in the future.
I give you credit for trying, but your approach is wrong. Time to try kindness, patience and reward. Build some trust, and a bond then you can work on respect.
“Beware of false knowledge; it is more dangerous than ignorance”. George Bernard Shaw