Hello, Welcome to Just Answer and thanks for your question. No one can know what is wrong without examining you. Swallowing a flea would be something you would remember, and wouldn't cause your symptoms anyway. They are most likely a combination of your anxiety disorder plus worry about your father. You should see your primary provider tomorrow if you still have pain. Diarrhea can be from anything to a simple gastrointestinal virus to irritable bowel syndrome that is aggravated by stress.
No one can tell you for sure online what is wrong with you. You are probably just stressed out. Your doctor can do a urine culture and see if you have an infection, or some other reason for frequent urination.
Of course it isn't life threatening. Get a grip, Tesa. The only way to know if you have a urinary tract infection is to do a urine test at the doctor's office. You can't tell it any other way. Other reasons for frequent urination are anxiety, diabetes, drinking too much water or beer, some medications (diuretics, decongestants, etc.).