I hope you feel better soon.

Listen to your body and give it what you need. A few days of eating what you do not usually eat because you are sick is not going to do any long-term harm. I got a bad stomach virus two weeks ago (up all night vomiting) and the next day all I could eat was plain toast and Sprite (two things I haven't had for eight months). I ate that for a day and then got back to lowcarb. I did have cravings for a few days, but I think that was as much from being starving (I dropped four pounds in one day when I was sick) as from eating the extra carbs. Three of the dropped pounds came back, but one stayed off and two more have left me since then. The important thing when you are sick is to do what you need to speed up your recovery.