Getting a bit of fresh air through a slow walk in the garden helped my digestion and eased my nausea, but do it only if your doctor has allowed activity.
While fighting nausea, make sure you don't skip your medicines, especially thyroid ones if you have it. If you can't keep anything down, do ask your doctor for safe anti-nausea pills.
Try eating small meals every two hours instead of three large ones. Keeping a little food in your stomach stops the acid from building up and causing sickness.
Look, if you are throwing up everything and losing weight, stop trying home remedies. Go straight to your doctor and get a safe prescription, don't suffer.