Attachment styles in relationships

Looking for some insight on attachment styles and relationships - specifically for me with my BF. He's Avoidant/secure, I'm anxious/secure. I'm working on me, he's been working on hi a long time as an individual. When it comes to us, his Avoidance has shown up in a big way and I'm trying to learn more.

How does someone like me, help, support etc him in opening up from avoidant? I'm trying not to chase and push (yay anxious) but I'm really craving more connection so I'm not sure how to go about it. We are both divorced so we aren't young or inexperienced in relationships. I'm hoping I can learn more to help him feel more secure and less avoidant, if it's even possible.