UTI is finished but still symptoms are available. What should I do? Can there be other diseases with these symptoms? (i don't have diabetes)

Other possibilities. The answer depends on the symptoms. Urinary frequency give you a different list of possibilities than pain with urination, or discharge. UTIs are not as common in men as they are in women. STDs can give similar symptoms. All antibiotics do not treat all problems and if you were treated for a UTI but really have an STD you may need a different medication.Be evaluated for the appropriate treatment.
Something else. UTI symptoms could be caused by vaginal infections or STDs also. Try a zinc supplement (25-50 mg/day with food) for 2-3 days. If symptoms don't resolve, then contact your family doctor for further evaluation.