It sounds as if you're having spasms. Have you discussed this with your surgeon? You should not be in that much pain. You are in the midst of the most difficult part of your recovery, but it seems to me that what you're experiencing isn't typical. If it only lasts a short time and subsides within a day or so, I'd say it was a quirky bump in the recovery road. It it lasts several days, your surgeon should be informed. You should not have to be in that much pain.
Joy's suggestion of backing off on your eating and sticking to liquids is a good one. Since you're having painful reaction to eating, take it very easy. Also, are you being careful with not drinking anything very cold? Iced drinks can cause pain. Be sure to stay away from straws as well, as they introduce a lot of air into your stomach.
I'm not sure if your surgeon told you, but your wrap is becoming increasingly more swollen during the first two weeks of recovery, and this swelling can cause a lot of discomfort at the wrap site, and make swallowing difficult.
In my experience, the incision site at the left rib was the most painful of all, and the pain lasted the longest. When I questioned my surgeon, he said that that's the port where most of the work is done when manipulating the surgical tools.
Again, I can't emphasize enough the importance of letting your surgeon know that you're having so much pain. Generally there is not a lot of pain with this recovery, so he/she should be made aware of your difficulties.
Good luck! Let us know what you find out and how you're feeling!
Words of wisdom by Eckhart Tolle:
"Whatever you fight, you strengthen, and what you resist, persists.”
“Worry pretends to be necessary but serves no useful purpose”
“Accept - then act. Whatever the present moment contains, accept it as if you had chosen it. Always work with it, not against it.”