what were you doing before, and why do you think it has 'gone south', so to speak? explain the things that are happening that give you to say/think that your horse no longer 'respects' you?
who handles your horse on a daily basis? while you were gone?
has his/her life changed a lot recently? such as type of boarding, equine companions, food, riding /exersize amount . . . . Consider the whole picture.
tell us about your horse's personality, too. if you don't mind.