I think you did a great progress.
My paint was like that too when she arrived. What I did was lots of talking and brushing (and treats were not the last in process even though some people are against them). I also did hand grazing with her. In couple weeks I added round pen work (like free lunging, backing, etc.). My only advise would be try to involve other people to communicate with her (petting, grooming, walking with you), so she wouldn't turn "one person horse" with trust only into you.