Frequent urination doesn't suggest STD of any kind. It is often a symptom of stress or anxiety, especially when the source of anxiety is concern about genital health. So I doubt you caught an STD, and I doubt anything is wrong except for anxiety. But if your symptoms persist, see your health care provider or your local STD clinic for examination and reassurance. You can expect that nothing abnormal will be found.
Best wishes-- HHH, MD
Also I have been masturbating a lot since the encounter. Would that add to frequent urination?