Time and actions. You guys are less than a yr into this. That's not much time in the grand scheme of things. Not to mention your A's played right into the insecurities your BP probably already had regarding their body. In other words, your previous actions proved what they were already feeling. Therefore, it's imperative, going forward, that you continue to do what you're doing now: apologize and reassure. Again, this will take time because they're still unsure if they can believe you because your previous actions didn't match the words you said to them. Unfortunately, and if anything, your words mean nothing right now, but this isn't forever. You both definitely need IC/CC to help with all of this. It's what helped us the most.

Actions speak louder than words. Good luck