What Causes Frequent Urination After A Rezum Procedure?

I just had a procedure called Rezume for BPH about 9 days ago on the 26th of December.. The catheter was removed this past Tuesday, January 2nd. 10am. The office had me come back 4 hours latter to ultra sound my bladder and they said is was 60% empty and sent me on my way. The first day I drank allot of water and things seemed OK until about 6 hours ago. Now I have urge to pee every hour and it is a real strain to urinate. Are there any certain symptom to look for before I go to the hospital emergency. It is just before midnite and my doctors office won t open until 8 am. I don t want to make a premature trip to emergency. What should I be looking for in the way of severe symptoms. If I fall asleep it seems harder to urinate. If I am awake it is easier to go.