The EC Process is both simple and complex to grasp. If you spend some time with the EC books, you should be able to comprehend the logic of the steps, but to apply it to yourself is another story, and takes courage, intelligence, and maturity. You seem to be doing quite well with this, but you are still in the beginning stages of self-work. What you are describing is actually a text-book experience of becoming aware of yourself and your projections, reigning in the knee-jerk blameful responses, and replacing that with a more enlightened approach.
You’re working with the Significance center. We assume there is substantial negativity accumulated there, which takes the form of feelings of inferiority. This gets projected, as described in the books, and then you fight the projection. Becoming aware of this syndrome is the first step to psychological self-awareness. How to transcend it is what the books are all about.
The anger is a first-level emotion. You can work with it in your meditation and eventually it calms down, but it doesn't happen overnight. Ceasing to outwardly express the anger and working with it inwardly is a major challenge but it can be done. You might add some physical activity to channel the anger into if you feel it might be helpful, but that's not imperative. Is there a middle ground for justified outward expression of the anger? I don't think so, giving way to the anger is always a form of self-rejection, but on the other hand, you have to be moderate with yourself and not expect to be able to maintain perfect self-control immediately.
After the first-level emotion of anger comes the core feeling of not being good enough, being inadequate, feeling disrespected. This is where the critical work must be done. I have tried to describe the work in detail in the books. You can work with both these feelings in your meditation. Visualize a scene, let the anger come up, process that, and then go to the core feelings behind it. Keep shifting between them as needed.
You're going in the right direction, as you realize. You just need to stay with it and have confidence that it will result in a major life inner healing.