Need help w resources: beginner PA info on honesty/disclosure!

I know there is an excellent vast amount of resources here already (thank you!), but either I am not finding exactly what I need yet or hoping someone knows additional resources:

I don't need a beginner guide for myself but actually more geared towards, I won't even say a PA necessarily, but just a USER, who is still clearly in the mindset of "don't ask don't tell" regarding not only this but anything that might potentially upset me in the relationship.

He has agreed to therapy which is great, but not only does that still feel far off due to finances and finding the right person, but I also don't have faith the therapy will work out well because he is really REALLY an avoidant attachment style person and this is my last ditch phase of this relationship to try to convince him that

1. The only way to gain trust and move forward is to be able to say the things that he knows will hurt me, as long as I make that environment safe for him to admit it all. He needs to understand that admitting things even though I haven't outright caught him in a long time is a better step forward than just waiting to be caught.

2. He needs to be honest with me even if it's because of the realistic struggle that he does not find me attractive right now because I suddenly gained a bunch of weight. Any resources you can point me to about why turning to porn when your partner becomes unattractive is only going to make it worse, not better? I can empathize that I don't look good all the sudden (thyroid issues) but the sudden complete drop of our sex life is not believable that everything is fine for him...he is just absolutely adamant not to admit it.

I just am really looking for any at home pre therapy things to read together to hopefully get this started before I can't handle it any longer, any help appreciated