what can be causing the burping?

-I had bad heartburn after my third chemo, but was given a medication called Lansoprazole which seems to have sorted it out like magic.

- Is there anyone you can consult with today from the medical center where you're being treated? Perhaps, they also have some suggestions on what you might be able take to get some relief. I recall having some indigestion after one of my AC treatments, but I blamed it on having a spicier meal than what I usually ate 2 days after the treatment. That night I also had a fever. I think I wound up going on an antibiotic that time. I don't think I took anything for the indigestion, though, but just started eating bland foods again and was okay.

-My wife had stomach problems during her chemotherapy. Her oncologist prescribed Zoton for her which improved things greatly. It should be possible to stop your sickness too. My wife had a combination of ondansetron, metoclopramide, cyclizine, haloperidol and dexamethasone prescribed at various times in each treatment cycle to stop vomiting. If the details would be of any use to you, please let me know.