I had an operation and I was not allowed to drink for three days, then they let me drink water and juice only for three days. The next day was the first day of Ramadaan, and the doctor told me to start eating on the first day of Ramadaan. I did not fast on the first day of Ramadaan because I was very hungry, and I could not fast, and I will not be fasting on the second day of Ramadaan either. Is this permissible?.
It seems that you are exempt from fasting, because you are still unwell. Allaah has waived the obligation of fasting for those who are sick, as He says (interpretation of the meaning):
“but if any of you is ill or on a journey, the same number (should be made up) from other days”
[al-Baqarah 2:184]
It seems that it was permissible for you not to fast on the first and second days of Ramadaan because of your being sick. What you have to do is to make up these two days after Ramadaan ends. You may fast them separately or one after the other, depending on what is easiest for you. It is better to hasten to make them up straight after Ramadaan ends.
And Allaah knows best.