I've found it is best to just let it come back up; just let it return and the pain will be gone. I know, it sounds gross, but it works.
Sadly I have had it a few times...and last night's was the worst - it lasted 1.5 hours :( I ate 3 oz of chicken too quickly, and it was kind of dry. I felt ravenous, eating dinner at 8:30 at night (after a hair appt) since I hadn't eaten since 1:00. I am so sorry you are experiencing it. It's definitely a learning experience!
I have had a lot of problems with the foamies after years of gobbling my food down as fast as I could so that other people wouldn't notice how much I was eating.
What has helped me the most was a hot shower. If you are home and able I found that my whole body relaxes under the warm water and that includes that my nausea