Sweetie, said with kindness and compassion here, you need to seek help for this. I'd love to see you work with a psychiatrist. A lot of what you are focused on is eating which does bring to mind an eating disorder. Have you ever been diagnosed with one? There are specialists in the psychiatric field that focus on eating issues, hon. Ask your General practitioner or OB for a referral. Talk therapy is going to be important as well. What is the root cause of your anxiety? How is food so intertwined? Those are important questions.
Most people when highly anxious do not feel hungry and can be queasy even. I do think that is normal for many. But this seems a bit deeper than that. Either way, treating this anxiety head on and full force can perhaps change the direction this is heading. Let us know if we can help!
I'd guess you already had an eating disorder if you were only eating one meal and a snack a day. There's no way to get sufficient nutrients that way. Are you seeing a therapist or anyone for this problem? It seems to me you have an eating disorder caused by whatever is causing this anxiety, or that's the way you're focusing on it. Get some professional help.