Hi Cathy, It seems as if your H needs a lot of reassurance from you that you DO want him and that you DO WANT to me M to him.
I like KAW's idea about leaving greeting cards for your H; little notes to let him know how much he means to you.
I also like your idea about a surprise 50th birthday party for H! So what if OW finds out; it will be YOU who plans it. It's your place after all; not hers.