17 Months Post-Op - Feeling Full Quickly

Hi all, it's been a while since I posted but have a concern and wonder if any of you have experienced it. 

I am 17 months post-op and have reached my goal weight, but for the past 4-5 weeks I am unable to eat per my dieticians suggestions. I think I am making good food choices, but after a couple of bites I start feeling incredibly full. I have started supplementing protein drinks again just to meet my protein requirements.

Thanks for your feedback.