This sounds like a very troublesome situation. If you are truly unable to produce any urine and have not done so for more than 6 hours, this could be a medical emergency and you should seek medical attention immediately!
If you are still able to produce some urine but are having more difficulty starting or maintaining a stream, this is still an issue you should see a physician about right away. Your primary care physician
should be able to address this as opposed to an emergency medicine provider. Your doctor
will want to hear more about your symptoms--what do you mean when you say you are having this kind of difficulty? Is it stopping or starting or maintaining a stream? Does it occur all of the time or intermittently? You’ll want to discuss these various aspects with your doctor.
Depending upon your age, gender, and prior health history there are several things your doctor will want to consider. First, if you are an older man, it is quite possible that an enlarged prostate is contributing to your symptoms. If you have a prior history of kidney disease, you may have an obstruction somewhere in the urinary tract. Your doctor will want to examine you and may also want some additional testing including blood work and some imaging such as an ultrasound
of your kidneys. Book an appointment with your doctor as soon as possible!