My hamster is weak from wet tail. How do I feed and hydrate her?

It is very concerning that Camilla is too weak to eat or drink - I would recommend consulting with your local veterinarian who prescribed her medications, as she needs to be evaluated again. She should have improved, or had her signs resolve, by now and she may need to have her medications switched.
Hamsters can lose weight very fast, and can also dehydrated quickly, without food and water. You can use a small syringe to try to provide her with water, however please go slowly as it is very easy for hamsters to aspirate water or other materials into their airways and lungs.
The discharge around the eyes can be cleaned with a warm, wet cloth. This may be occurring because she doesn't feel well, or it may be that she has an infection going on as well.
For food, your veterinarian can provide you with a powdered food that can be mixed with water and given to Camilla.
I hope that gives you a place to start, and I hope that she feels better soon.