Why should YOU change for him ?
You have done nothing wrong at all, so don't hate yourself.
I feel so much sympathy for you, but sadly this kind of thing can happen now that the internet has made it so easy for someone to strike up a relationship and then get on a plane, without having time (or even the intention) to get to know the other person properly.
Do keep posting Lynn, as there will always be good people here who will share their thoughts with you.