"he's very social, he loves to be pet".....
The above from your second post on this, is the crux of the problem.
You have created a spoiled horse.
Also there is good chance horse is not being aggressive but is just full of himself from being stalled too, and you don't have enough experience to realize that, or deal with it either.
And furthermore, if your brother was riding in the arena? You had no business trying to take an unbroken horse in there period. Doing that is just asking to get someone hurt or killed.
If you don't get some help for your handling of horses as well as how to assess your surroundings you will end up getting hurt badly. Not if, when.
Letting a horse run free when acting up on lead line, is not going to fix anything.
Forget trainer. Sell these, get something already broke, and take lessons on handling horses.