Resentment & childhood trauma

30M here, step father to two children 6 & 7, the mother 30, we both know we have childhood trauma and we just realized I’ve been so resentful towards her ( lashing out, avoiding conflict, people pleasing, etc. ) I grew up with a single mother & she had different boyfriends all the time. I don’t really remember allot of the times but some I do.

I’m working on my traumas as I type this day to day now.

What can help and what is triggering my trauma so badly?

I’ve never lashed out, or been angry or this stressed out before.