How to work through resentment & rebuild trust ?

hey y’all looking for some advice. I (26) have been with my partner (25) for almost four years. He is seriously such a sweet partner & we have been poly since we started dating. I have had multiple serious relationships while dating him & he has always been nothing but supportive & encouraging. sometimes he’s so supportive & “perfect” it makes me feel like the weakest link in the polycule lmao.

I have struggled with jealousy since i was a child & in our relationship i would feel critical of him & his partners / insecure about myself / anxious about our relationship when he would start escalating w other partners. ( boo terrible behavior i know) Change would make panic like everything i built just crumbled to the ground & i have a deep rooted need to predict the future to feel safe. Ever since i started going to therapy & was diagnosed w cptsd i feel like everything is starting to make sense. I understand what triggers me & how i can regulate my emotions so that my partner doesn’t face the brunt of my trauma and mental health moments. it’s been about 6 months of therapy & for the first time my values and actions are aligning. Also Irene Mornings book the polyamory paradox literally changed my life ~ cptsd lens on ENM.

But I just know that i made so many mistakes in my past with my partner & i don’t know how to move through it & rebuild trust. They are the kindest most empathetic soul and understand why i was struggling so hard & how i legit didn’t have to tools to keep my anger & emotions in check. but i know that there is so much resentment built up between him & i :( specifically i think he resents me for not being as “good” at polyamory as he is. He doesn’t show much remorse for lying to me & he no longer tries to see why i am upset about certain things. there’s moments where i feel like im crazy for being upset about something but dont feel like i have the right to be hurt about anything he does now because of the way i have acted in the past. I don’t want to like throw away our relationship & start a blank slate w someone new bc he’s truly one of my soul mates. :,((

does anyone have advice on rebuilding trust and working through resentment. Bonus points if the person who is resentful feels guilty for feeling resentment & struggles identifying / articulating their feelings. Also how do you forgive yourself for your past poly mistakes & how do you know when you’re healed enough to be polyamorous & not like hurt yourself your partners & your metas.