While I can’t comment on the SR aspect, I’ve noticed that the same things can occur with fasting and other practices where some stimulation our minds are used to are removed and underlying issues that we can usually easily repress come to the surface. So I can’t help but make the connection. Usually, whatever is coming up needs to be addressed and released because even though we are not aware of their effect in our previous regular circumstances, their effects are always there, albeit more subtle.
But this may all be things you are be aware of, you seem to already have a solid physical and spiritual hygiene. If it were me, I’d make it meditation sessions where I focus solely on the anger and let it come out, without engaging the mind, until it comes to it’s natural refractory period. Using https://forum.enlightenedstates.com/t/new-release-the-internal-alchemical-crucible/12604 might help 