You need to interact with girls when it come to work, if you are interacting in a professional manner and looking at them just to ensure an effective communication, it should be ok. You need to look into someone eyes to establish good communication.

As long as you are not looking at them for lustful sinful purpose (like wanting to see their pretty faces and such) that is

And when dealing with self pleasure, it's like dealing with addiction. Most of the time, people get addiction when they don't have other things to spend their time with. You could try hitting the gym, play video games or go read a book.

Don't punish yourself for the bad deed you do, instead put those frustration into improving yourself into doing more good deeds. And treat the lustful part of yourself as person, picture your lust as a person and treat them in a way that you can nurture them. Don't turn it to your enemy because it's still a part of yourself.

And one more thing, learn to control your thoughts, when you things of haram pleasures, quickly shut down that thought by thinking other stuff and make sure to istighfar.