Let me answer you by offering two different but complimentary angles.
First, your anger isn't the problem, what's the problem is the balance between your anger and your self-control. Assuming you've fully analyzed the merits of expressing your anger through violence / escalation versus the merits of exerting self-control and abstaining from violence / escalation in a given situation--assuming that you've played out both hypothetical scenarios to their logical conclusions and that no emotional repression is obstructing a rational evaluation of any facets of the equation--then you must decide which option to choose. Mainstream thinking tends to reinforce the notion of enlightenment as unattainable and of ignorance as mandatory, and it's easy to get caught up into thinking that you're in a conflict with yourself and that for part of you to win another part of you has to concede. You vie to overcome that which is already you as if the choice exists in isolation from the chooser, as if it were possible to overcome yourself or possible for a painting to exist without a painter, desperately clinging to emotional impetuses insisting in the name of justice in some idealized court that other emotional impetuses you also feel are wrong. In reality your emotional impetuses must be considered some distance removed from the underlying beliefs and convictions supporting them, for in general your emotional impulses are in perfect accord - you seek justice - but in specific, conventional contexts justice isn't perfect and compromise must be had, compromise with which under the cold gaze of logic you may walk in perfect conviction, integrity and nobility. In other words, at issue is only to act, to recognize there are clear obstacles before you and to choose the least worst of the available options or, better yet, to think outside the box and find a superior option. But when we get trapped in back-and-forth inner conflict, we can't see the clear options before us, much less manage to think outside the box.
Second, your anger isn't the problem, rather the problem is your fundamental convictions, values and things in life which hold meaning to you or in which you choose to find meaning. You're decently employed (or at least not unemployed), OK, you've got a girlfriend you care greatly for, sure, you may love your family or friends, fine, you may have pastimes, hobbies, or intellectual pursuits you care deeply for, lovely. But if you're willing to jeopardize these things for the sake of letting off some steam, for the love of god man it's one of the greatest lies of modern times that you have a problem with 'responsibility' or 'self-control' or that you've got 'issues' or 'things to work through'. In the name of logic itself, you aren't a fucking flaring moron, you aren't willing to exchange $1000 in return for $1, that's an utterly ludicrous transaction. You were willing to engage in violence / escalation because your beliefs and convictions about bullying were actually potent. What of your supposed love for your girlfriend, family, friends, job or lifestyle? It's hollow, and they want to feed you a pill or give you a bible for it... it's merely "some stuff to work through". When psychologists point out as the adage goes that it's not a sign of mental health to be well adjusted to an insane society, they're faulting the society, and I urge you to consider the solution is to muster with the utmost urgency and passion your entire being towards piercing this hollow shell of a society by acquiring the hidden knowledge which lies beyond the facade--metaphysical foundation, philosophical meaning, spiritual understanding, whatever you want to call it, more than some issues or things to work on, something that makes you get out of bed with a passion every morning and allows you with the righteous, cold certitude of logic to embrace your own self as the true center of your universe so that you can then engage the world without looking backwards through your own perverse reflection.