UTI can cause a low grade fever, because it is a bacterial infection.
Assuming you have never shared needles with anyone or been exposed to anyone with hepatitis C. The UTI should be easily treated.
Cantharis — this is the most common and considered the most effective homeopathic remedy for UTI.
Cantharis can have a side effect, it can increase sexual desire in women. (I'm sure you must have heard of spanish fly?)
You wanted to know more about the coating on the tongue.
Candida is treatable and is not rare, but usually requires a special diet and about 6 months or more to get rid of it.
A white coating on the tongue means you have candidiasis. also called candida, Candida albicans or oral thrush.
It is fairly common for Antibiotics to cause this problem, and may not show immediate symptoms after completion of Antibiotic therapy.
Candidiasis is a fungi that is caused by too much yeast in your body, as the result of Antibiotics or some other toxin destroying the friendly bacteria in your body. Antibiotics can also cause vulva vaginal candidiasis, causing an itch and possibly a discharge.
If the tongue is yellow, it could be because you drank something that discolored it.
If the tongue has a yellow coating that stays yellow we will have to discuss this further.