RES Turtle- health problem- help

Question
I'm really desperate and hope you could help me i really want to save my turtle. I have a RES baby i got it a month ago from a friend who had her for about 3 months. She is really small 4 cm (1,6 inches carapace length. Since i have had her she hasn't really eaten anything and in the first week her eyes got puffy the second week they got closed and she now hasn't eaten in like 3 weeks although i always try feeding her 2 times a day.
My answer your above questions: Tank size 40x30x25 cm( 15,7x11,8x9,8 inches), water temperature 82.4 F(28 degrees Celsius- that was recommended to me by the owner and the pet shop the original owner got the turtle from,heater, water thermometer, filter, UV Lamp (Sun glo-neodymium Daylight Lamp-15 W). I used to use tab water which i left about 24 hours so that the chlorine would saddle down and afterward i treated it with ReptoSafe. As far as food goes i tried giving her Gammarus and Reptomin pellets the previous owner told me that Gammarus were her favorites, sadly she didn't any of them so far i tried fine minced carrots and cabbage, didn't work either.

Now again to the eye problem, i suppose that is why it isn't eating. As soon as i figured out that something was wrong i went to the pet shop first and they gave me tartabel (turtle eye lotion)after seeing no improvement i went to the first wet who told me it was because of vitamin A deficiency and that i should put vitamin A drops on its eyes, didn't work either so i changed the vet. The second one told me as well that it was a vitamin A deficiency but advised me to move her to a smaller enclosure an to put 10 drops of vitamin A in the water and it kinda worked it is now opening it's eyes occasionally but is still not eating anything. Due to the oily vitamin A drops i am now changing the water daily and am using bottled water with no bubble of course instead of tab water. 2 days ago i noticed a gooey substance on its head and front legs which i am now cleaning off daily with a swab, today i went to see the vet again without cleaning it up and asked him if that was coming from his eyes or if it was a result of the oily vitamin A in the water he couldn't answer my question and told me co continue with the same treatment and get back to him in 2 days. What can i do to make him better. In my country the vets are not really experienced with reptiles so i don't know if i can rely on this vet, i don't know any other vet though so i'm desperate. How can i help my little friend ? How can i at least make it eat because it hasn't eaten in about 4 weeks!!!! i've read a lot of things on the internet and one treatment i found was an injection of vitamin A but because the turtle is so small the vet told me that it is tricky to get the dose right and that an overdose might kill it. What should i do ? how can i help ? what should i tell my vet in order to help him help my turtle get well again? I'm desperate or else i wouldn't ask on a foreign site for help. Maybe you could give me advice.
Thank you soo much for your help.

Best regards,

Cristina (Romania)

Answer
No vitamin A injections. Yes, they can be deadly. Especially a turtle this small. What you need to do first is ensure that everything you are doing is right, because it sounds like the turtle starting having problems after you took it home. I am assuming your friend had no such problems before?

First, you do not have a UVB lamp. The light you described is not a UVB light. You need to get one. A reptiglo 5.0 or something similar. Also, the light you describe is not a basking lamp either. 15w day time light is not going to do it. You did not give a basking temperature either. You need to have a dry basking area for this turtle, and you need a basking heat lamp in addition to the UVB light. The basking area needs to be in the high 80s-low 90sF. My estimation first is to figure out whether you have the environment all wrong. If the turtle does not have a basking area and warm enough temps, these complications will happen and it will not eat.

I recommend correcting this before going further.

Are any bubbles from the nose or mouth observed? Does the turtle breathe with it's mouth open? When it is in the water, does it float evenly or tilted to one side?

Attaching a picture of your turtle and habitat would also help.