Now, to move forward “also” have to let go of the anger? Once you give up on the anger what’s left? NOTHING!
Actually there's a lot after the anger FBM, although you can hang onto it if you want. It's not so much about letting go of the anger but moving through it.
As we know there are stages of grieving, denial, anger, bargaining, depression and acceptance, not necessarily in that order, but it is possible, and normal, to work through all of them when we've had a significant loss. There are also the stages of detachment over there -------->
not sure if you've reviewed those lately and know where you are?
It's great that you're acknowledging your anger, that's stage one of detachment BTW, and it's great you're getting introspective and focusing more on you rather than your ex, that's progress.
Ignoring your feelings is not a great plan, seems you're aware of that, and when we ignore our feelings they don't go away, they just show up somewhere else, and it's great you're digging into what's going on with you instead of repeating the pattern, that too is progress.
Take care of you!