Sex desire. Time to come back to normal?

Recently I had tooth abscess for which I had small surgery on my neck, while admitted in hospital i also suffered pneumonia and almost 3 litres of fluid was taken out through ICD treatment. I lost almost all proteins from my body and lost 16 kgs weight. It's been almost 2 months since I got discharged but problem is , I feel to urge to have sex but don't get erection for very long time and the desire soon goes off. What can be reason for this? I was on very strong medication in hospital and my haemoglobin level also reduced, which is now around 12. I still feel tiredness even though my diet is normal. How to improve this desire for sex and last long? Any medications to take or what can cause this? Is this due to protein loss or reduced haemoglobin? Please suggest as its affecting my personal life. Will it take some time to come back to normal?