No texting. Face to face. But not while naked or in public (of course!). Just sit down and have a conversation.
My husband has seen me weigh from 145 to 326. No lie, no exaggeration.
Communication is key in everything, yes? So talk, and tell him you would like for him to be more assertive.
And consider becoming more assertive yourself. He may love, love, love that and be waiting for you
to make those initial moves.
Also - a suggestion - Google plus-sized lingerie.
Find something that you love that makes you feel beautiful. I assure you, it is out there. Own it, wear it, and love your wonderful self.