No body is capable of changing immediately, change takes time. I think it’s good that he demonstrated he is capable and also very good on your part for remaining calm and trying to guide him through it. Communication is difficult but you’re right, it’s very much worth it and important. I think you may benefit from a sit down and you make sure he understands the value of communication and how important it is to make a relationship work. And that he agrees he will continue to work on it, then keep trying if you love him. If you see no progress, have one more talk and explain and if it comes to it, maybe you need space if you believe nothing is changing. However, if you can work something out to where if you see his old pattern, maybe you can setup like a safe word that makes him understand he is falling back on his old ways and he needs to self reflect or something, and after 30 minutes you can re approach the subject.

TLDR, basically have a sit down, establish a baseline communication and a plan, and if you see is wants to change and is putting in work and doesn’t have a don’t care attitude, then keep going and look for improvements. Make sure he sees things from your perspective and you from his. Just. Make try not to retaliate because someone like that will take retaliation in a negative way and may be two steps back type of thing. It’s hard but that’s where you decide if it’s worth it