If you can, you could try to eat the following: apples, crackers, something with lemon, ginger, or mint. These can help to settle the stomach if you're struggling with nausea. Eat a little at a time, don't rush yourself.
You could definitely substitute complete foods for a smoothie if you truly can't bring yourself to eat anything. Fruit may also help with hydration. I do really recommend ginger or lemon, though.
Drink plenty of water. You may find hot water with lemon to be refreshing.
You could try some mindfulness/meditation to help soothe your anxiety. There are some apps you may be able to download, or YouTube videos. Just try to do something that will relax you.
If at any point you feel like your symptoms are getting much worse, I'd recommend speaking to your doctor.
Hope this helps.