Here's my advice:
1: Back off on potty training right now. Give it a month or so to give him a good break. In the meantime, go to the bookstore and buy a few different books on potty training - kid books. Ones that you can sit with him and read or that he can sit and read and see other kids learning to potty train. We did this with our daughter for a little while before we started officially potty training her. I think it made it more interesting to her because she saw other kids doing it.
2: Once you do start potty training again, NEVER get upset at him (though I know sometimes it can be maddening!!). If you get too upset about it, just stop potty-training again. It won't hurt for him to be older.
3: When you start potty training - toss the pull-ups. Do NOT use them. I know some others will disagree with this, but when we officially started potty training, we tossed any form of diaper and went to a thicker pair of underwear (meant to be able to catch a little bit of urine).
Using underwear when he wets himself, he'll feel wet, and he'll get wet, and he won't like it. If he's in pull-ups, there won't be accidents and there won't be urine running down his legs - basically, what is the motivation for him in potty training while he's wearing pull-ups? Sure, it's messier, but it makes for faster learning. So, toss the pull-ups and diapers and use underwear, the thicker kind. Or even just plain ol' underwear. If you're worried about accidents, have him sit on towels. But, you're going to have to have a few accidents (or more) in order for him to understand why it's important to sit on the toilet. Try to give yourself a week at home with him (if it's at all possible) so that you aren't running to the store with a boy in the middle of potty training.
4: Take him potty every 30 minutes. It doesn't matter if he needs to go or not. Have him sit on the potty. He can even read the potty books that you bought him. The point in this is to get him in the habit of sitting on the potty to go (his brain needs to start thinking more about the toilet, and this will help get it to do so) and doing this every 30 minutes will also help to prevent accidents. I would personally try to make sure he pees every time you sit him on the toilet - even if it takes 10 minutes for him to. But do it nicely...no anger. Just let him know once he's done, he can get up.
5: Have some sort of reward system, though, I do highly suggest NOT having it be a form of candy. My sister did this and her daughters potty-trained great...until the treats went away...then so did their potty-training. She also used pull-ups and had a lot more problems than we did. Try something like a sticker chart. Each time he pees, he gets to put a sticker on the chart. Or don't do a reward system at all - just use lots of praise (or both) each time he pees, make it a HUGE deal. If he poops, make it an even bigger deal. Let him know once he is completely potty trained for a week (you can use the sticker chart to help with this to count the days down of accident-free days) then he'll get to buy a special toy of his choosing.
If he pees or poops in his pants, don't get upset, but do talk about how gross it is. Say something like, "Oooo, yucky! You are all wet and stinky. It's not fun is it? When you need to go potty, sit on the potty and go, it'll help keep you clean and you'll get a sticker! Won't that be fun?"
I wouldn't try night potty training until he is successfully day potty trained. When you're ready for night potty training, buy some bed covers (things to protect the sheets and if they get wet, all you have to do is pull the dirty one off and put a clean one on - makes for an easy clean up). Don't use pull-ups. Wake him up 2-3 hours after he goes to bed and have him pee...whether he's awake or not! It'll help teach his body to wake up at this time to pee. But that's a story for another day!
Good luck.