6 months after Nissen stomach has slipped up!

Hi all!
Well here I am 6 months after my Op and today I saw my surgeon after an endoscopy on Monday.
He tells me I’ve had a 1 cm slip of my stomach and some burning from reflux but the fundlopication is in tact. He also said I have delayed stomach emptying so I’m on Nizatadine to help with the emptying and acid levels.
His hope is the meds and improved emptying will make a difference and after another three months I can wean of them. As you can imagine I am so upset! I have been told since early on that heartburn feelings are the brain reacting to the surgery and thinking it’s reflux. Well for me it’s not that simple!
Has anyone heard of or experienced any of this?
Thanks everyone
Rosie