I'm so glad you were able to get out of that relationship, and that you're now in one that feels safe and loving to you.
"Draining" is a really excellent way to describe the process of unlearning the habits you developed in order to survive and abusive relationship. Because it can be exhausting to run a calculus of "is this safe, will this set them off" for things that you know intellectually are no big deal. That's one of the many awful things about abuse; it teaches us patterns or habits that help us stay safe, but then those habits can be wired in there pretty deep.
I can't say how long the process will take, but I do want you to know that communicating likely will get easier over time. Both because you'll get more practice doing it and more time to heal, but also because you'll hopefully continue to be with partners who let you know it's safe to ask for what you need.
You mention having made some big progress in your healing, which is great. Did any of that healing happen with the support of someone like a counselor? Too, have you had any spaces, be they a counselors office, or with understanding friends or family, to just sort of practice communicating?
I also just want to check in on how you're doing in general; there is a ton of stressful stuff going on in the world right now, so we're making it a habit on our boards to touch base with our users about how they're doing.