My 7year old male dog is straining when he urinates and most of the time it is a very small stream his penis seems larger then normal and he acts like it hurts to go what should I do

Take him to the Vet.

Let's see if I can figure this out - the dog has a swollen penis, he is having difficulty urinating, he is in pain and you don't know what to do.

Do I have that right?

He needs to go to a vet - he could have stones and runs the risk of having his urethra blocked.