I(24f) need advice, I clearly don't know how to maintain a healthy relationship.

Welp, I typed up this long wall of text hoping to gain some further insight but ended up just deleting it all because I know what my issues are, I just don't how to go about fixing them I suppose.

Don't know if this is relevant but my parents were never married, they were/are drug addicts and in my upbringing I've experienced a lot of physical, emotional and sexual abuse. I've gotten some counseling in the past and I plan on pursuing therapy in addition to implementing weekly exercises soon to help ease some of my anxiety and depression.

Quick summary: Last long-term relationship ended mostly due to lack of communication/sexual incompatibility. Current relationship is shaping up to be similar, roles are kind of switched but it is now suffering because I tend to shut down at any sign of conflict and can't communicate effectively. On the other hand, I'm growing resentful because I don't feel sexually satisfied even though I'm putting all my effort into making sure my partner is, even if it means going out of my comfort zone (which I've grown to enjoy eventually).

How do I go about becoming better at clearly communicating my problems when the moment becomes heated? I don't react well to conflict, especially shouting but my partner is the opposite though they've only yelled at me a couple times. They prefer to hash things out in the moment, whereas I'd like to cool down to ease my anxiety then revisit the situation. They know this. (I consider this to be a small accomplishment on my part because the old me, in my previous relationship, loved to just cut into the problem but our issues usually went unresolved that way so now I would rather process things first).

How do I become an effective communicator in getting my point across in a clear and concise manner even if the situation proves to be tense? Also, do I have unrealistic expectations in wanting my partner to be more genuine and expressive in the way they show me love and affection? I feel like a broken record, and quite frankly it feels crummy having to tell them repeatedly what I'd like to see/hear more of. I know people aren't mind readers but I've told them countless times and I can't help feel that if it's not there then maybe it isn't meant to be...?

TLDR; My romantic relationships are shaping up to have the same issues. I realize I have a lot to work on in maturing to be an effective communicator etc. What's my next step?