I'm just offering support, not advice, as I am in a very similar situation. My son is 3 yrs 5 months old, and using the potty has become such a power struggle, it's driving me crazy. He knows how to do it, knows he should do it, but, honestly, playing is WAY more fun, and he doesn't want to leave anything fun to do something that he now screams "is boring!" We let him run around naked all the time, and he uses the potty more, but not consistently. And as soon as there is ANYTHING covering him, he just pees when he wants.
We started out using little rewards when he used the potty, and I think that backfired on us. Because once he got pretty good at using the potty, I said he now only got the reward for something harder... and then he simply said "no prize, no potty."
The other mistake I think I made is making it too easy when he has an accident. I would run and get clean clothes, clean him up, clean up the floor, and he just got to keep on watching tv or squirming around to get at his toys. I will say "Ok, time to wash hands" and he'll say "Why? I didn't touch anything dirty. You did."
[REASON TO POTTY TRAIN MY 2nd SON EARLIER: A 3.5 yr old has too much reasoning ability.]
So I think I'm going to back off for a bit, and let him stop associating potty with reward. He loves being naked so we'll continue with that, but now when he has accident is to make him stop whatever fun thing he's doing, and go through the motions with me. Hoping that he'll realize that if he has to take time away from what he's doing ANYWAY, he may as well use the potty.
I blame myself too. But you know what? There are a lot of kids and parents who struggle with this. And while I often feel my child WILL in fact be the first kid to go to college in diapers, in my head I suspect we'll work it out over the next 2 or 3 months. His time schedule, not mine. Be kind to yourself, too, in this whole process. It's tough.