There are no two ways about it - your cat needs veterinary care immediately. UTI in a male cat can develop a blockage. Once a blockage occurs, it is only a matter of hours before it is too late. At this point, this is an emergency, and deserves the extra money spent on paging your regular vet to meet at their office, or even going to a emergency clinic. You do not say why you cannot take the cat in until the weekend, I don't know if it is a transportation issue or a money issue, or what. Beg or borrow the money or the car, but please get this cat the veterinary care he needs NOW.