Thanks for the additional information. I think your dog really needs to be examined by a vet. Based on what you are describing it sounds like he may have herniated a disk in his back. Other possible causes of paralysis can include a stroke to the back end. If he did herniate a disk and is not able to walk there is also a strong possibility that he isn't able to urinate appropriately because the nerves that go to the bladder are always compressed in dogs that can't use their hind legs due to disk disease (because these nerves are near the nerves to legs in the spinal cord and if one is compressed the other is too).
Usually when disk disease leads to paralysis it is a surgical condition. Surgery to remove the disk material that has herniated in the spinal canal needs to be performed if there is any hope of him walking again. Surgery can cost thousands. After 72 hours of paralysis there is a very strong chance that even with surgery these patients won't walk again.
If he suffered from a stroke, there is a chance that he may slowly regain function of his legs with time; however unfortunately many of these dogs never walk again.
It sounds like he is really painful and that leads me to believe this is disk related. I think he needs an exam by a vet to see if there is a chance to help him recover (be it with surgery or with medications).
Tylenol is toxic to dogs and should not be given any more. Usually dogs that have been given Tylenol will vomit at first but Tylenol can cause the kidneys to shut down and can cause seizures if the dose is high enough. In addition, Tylenol can cause stomach ulcers and bleeding in the intestines.
Aspirin is a bit safer although still carries risk for bleeding of the intestines.
For now I would not give any more of either of these medications. He needs to be on heavy pain medication and steroids. In addition muscle relaxants should be prescribed. Depending on where you live some of these medications may be available to you over the counter.
I have attached some information on disc disease for you to read. Please let me know if I can be of further assistance. I hope that everything turns out okay but I'm really worried right now for both of you.