If your SLP has never worked with someone with your problem then you need her to refer you to an SLP who does have the experience! I cannot urge you enough to see a SLP with a lot of experience - it can make the difference between eating again and never eating again. What you describe is actually quite common - the upper espohagal sphincter sounds like it isn't opening to allow food and fluid to enter the esophagus - was there a referral to a GI MD made? They usually like to take a look at those things and assess for the need to dialate or stretch that sphincter.

Your surgery wasn't too long ago - it could all be related to residual swelling too. Swallowing is a complex process that we take for granted until we can't do it! Keep up the effort!!