Girlfriend is sick: What should I say when texting?

The most important thing is to send a carefully prepared speech.

Try my suggestion:

Honey, are you feeling better? I have no appetite because you are ill. I've been worried about you. Do you want something to eat? I will buy it and send it to you.

Say you have a fever. I'll buy you some preserved egg lean porridge. Finally, in any case, if you feel uncomfortable, just call me.

I am right in front of you.