How do I 29F get out of unhappy/hard times in an 8 year relationship with 36M without splitting up?

Background: I (29F) and SO (36M) have been together 8 years and are engaged

It’s not that things are all bad or that we are never happy, but they’ve been needing to change badly for about 2 years now. Our conflicts, on my end, seem to stem from overthinking disagreements or differences, sensitivity, occasional jealousy, and struggling to ‘bounce back’ after there is conflict. Sometimes, I’ll realize I’m making a big deal or inappropriately angry about something that does not need to be but struggle to not act on it. I’ve gotten into the habit of satisfying that emotional urge to express myself or act upset. As a result, my partner will sometimes refuse to talk to me when things start to get out of hand. And this then creates a situation where I get desperate/call repeatedly/struggle to step away. He feels like he tries so hard to give me what I need, then feels like it’s not enough when he isn’t at his 100% and I am sensitive to it. We have different conflict styles in that I anxiously try to get closer and talk, where he likes to take space. We have really been deeply in love and many of my happiest moments have been with him. We met when we were a little emotionally unavailable, which at its worst resulted in a breach of trust on his end early on (and he put in the work to make amends and show that it isn’t who he is and I could never say that he does not truly deeply love me), and that incident has been the reason for some jealousy/insecurity now. we do things to be considerate of each other and try to make each other happy. There have been improvements over the past years to deal with our issues, but not enough to be in a good place now or not post this on Reddit lol. I am also signed up to start therapy to see how that helps.

I’m not sure how much more detail to provide about my situation, but our conflicts and length of the ‘hard times’ is taking a toll on us. We know that things need to change as we are unhappy now. And have discussed the possibility of letting each other go because we want each other happy. There are so many wonderful things we see in each other though and there are great things about how we are as a couple and team.. and it feels wrong to walk away from that.

what would you do? Can a couple who loves each other and wants to change do it and let go of the hurt and happiness that a long period of damaging cycles caused.. how would you do it?