Pro tip: keep altoids or very strong mints with you at all times. They don't fix the burps but they mask the smell somewhat. And if anyone comments, just say you're dealing with a stomach thing — most people are understanding.
Also — drinking a glass of warm water with a tablespoon of apple cider vinegar before meals helped me. Anecdotal, I know, but the theory is it helps with stomach acid and reduces the bacterial fermentation. Worth trying.