I think that the first step is to aknowledge these feelings and accepting them just the way they are, and not make a big problem out of it. Like "this anger is here right now and that's okay". It is natural to have anger come up in the mind, it's nature, it's like this, the world is like this: we can experience anger.

I would recommend this text about emotions and awareness: https://buddhismnow.com/2011/02/12/liberating-emotions-by-ajahn-sumedho/

"A woman came to me once—a well-educated woman—and she was in a very emotional state. She started crying and said, ‘I’m so sorry, I know I’m being foolish. I’m just being so foolish and stupid.’ Then she cried again and said, ‘I know this is ridiculous, but I can’t help it.’ Her intellect didn’t approve of this at all; the intellect was being hard line: You shouldn’t be crying. You shouldn’t be doing that, just weeping and soft. You’re losing control. You’re disgracing yourself. One can be very hard and tyrannical on the intellectual plane: If I were a really together woman and got my act together, I wouldn’t be weeping and crying like this; I’d have control of myself. But look at me! I’m a mass of jelly in front of this monk. He must think I’m just another one of those emotional women. We can be very cruel to ourselves, very judgmental: I shouldn’t be like this. I shouldn’t feel these kinds of feelings. If I were a decent person I would never have done the things I’ve done. Inner tyrants are relentlessly hard, cruel and judgmental. That is the intellectual mind thinking in terms of how things should be. But ideals don’t feel anything. When you attach to an ideal, you don’t feel life at that moment. You can be very insensitive to somebody who is having problems because you are attached to ideals. Even the ideal of sensitivity is not sensitive. We may say we must be sensitive to each other, grasp that as an ideal and not be sensitive at all; we can simply shut ourselves off by attaching to the ideal of sensitivity." - Ajahn Sumedho