You need to "punish" her every time she pushes you, don't let anything go through. You have to be the leader (she won't love you less, on the contrary, she will trust you even more).
When she overtakes you, make her go back or use a whip stick .
You can also make her change direction, she will understand that YOU decide and not her and will assimilate pushing with something bad.
I hope i could help you, good luck :)
Mainly just being pushy, she does sometimes pull back and rear for no given reason :/
Have a look at Parelli natural horseman-ship (7 games) they work wonders
Go to basics like desezitising. Also prize him for good things. Make him know when he did something incorectly or bad.
Walking past you: have a lead line and just a halter and practice walking, every time the horse walks past you or doesn’t stop when you stop turn the opposite direction, eventually the horse figure out that he follows you actions the pressure will be released.
Personal Space: especially in the stall, take your arm and put it on the other side of the head and just move the horses head away from you every time (don’t result to smacking or yelling) or you can shoo him to the back of the stall when he acts up.
hope this helps, what exactly is your horse doing ?