I agree with others about him addressing his inner anger. It needn't be an anger management class, per se, but something to take a good look at why anger seems so over the top with yelling and silence. My exh would excuse silent treatments for not wanting to say mean things, yet, that anger simmered and grew into resentment both rational and irrational.
As far as inflexibility, are you talking about creating a family? Parenting is far from anything that a rigid person can handle without eventually blowing one's stack. Gosh, even the most laid back and patient person can be tested.

I hear you about wanting to sort it out for you and not because your mum wants you too. That could be an entirely different therapy type discussion for you if taking that path.

Best of luck whatever you decide to do.