Boys in general take longer to be ready to use the toilet on their own, and your son has only been at it for two weeks, so give him, and yourself, a break. The accidents are gross and frustrating, I know, but it won't last forever. I think we tend to get impatient once our kids start using the potty, and we want it all over and done with right away--understandably! But it's a big step for a little guy, and I think the bigger deal we make out of it, the more control it gives them because they can see how much we want them to go. Try to just back off and be very casual about it. Ask if he needs to poop, and if he says no, just remind him to sit on the toilet when he needs to and call you for help if he wants, and leave it alone. When he does go in his pants, remind him that big kids poop in the potty, and the next time he should go sit on the toilet. Say it matter of factly as a friendly reminder, not like you're lecturing or scolding. When he has accidents, put the poop in the toilet and have him flush it down. You can also get flushable wipes and have him practice wiping (maybe after you've cleaned him up a little). Have him wash up when he's all done. Don't make a big deal of any of it. When he does poop in the toilet, praise him, give him a small treat, and move on.
My oldest son was peeing in the potty for a month before he would poop in it. Fortunately he would insist on a diaper to poop in. At first I kept trying to get him to sit on the toilet when he said he had to poop. He would sit there for a minute and then say he didn't have to go. After three days of not going and then being really constipated, I just left him alone and gave him a diaper. I knew it wouldn't last forever. One day he was in the bath and had to poop. I had just gotten his little brother out of the tub and couldn't grab him immediately, so he climbed out of the tub and onto the toilet and before I could turn around he was flushing the potty. He never wore a diaper after that. Good luck!