I'm going to suggest something weird, so I don't know if I'll have people sick pitchforks after me but...why not invest in a physical journal?
Let's look at the situation: your H doesn't trust you, you broke NC and didn't even ask him how HE felt about contacting your AP and did it anyways, and his mind is most likely jumping to worse case scenario because of broken NC. Yet, he grants you access to a personal journal.
So imagine if you had zero trust in a person and they are typing away on their phone. His mind is probably instantly going to assume "Is she texting him again?" He could ask, but he can't verify this is what you're actually doing. So he'd have to just trust you...which won't go over so well considering things.
There's a popular phrase, "Trust, but verify." Right now your H has no trust and no way to verify to gain any kind of trust. If he saw you writing in a journal, he can verify that you are doing just that, therefore he's able to trust you when you say you are writing an entry.
Hopefully I'm making sense here but I think it'll help your H be more at ease, and THEN when you are using your phone to say text a girlfriend, you can proudly show that you are being honest with access to the phone. Me- WGF 22
Him- BBF 21
September 26th, 2013
"A lesson is learned. Life is. Simply. There is no Death. There is no Before. There is no After. All is in Flux. Simply."