Almost 4 year old still refusing to poop in the potty. I've tried everything.

In the last year I've tried rewards, treats, bribing, star chart, cutting a hole in his pull-up, trying to get him to poop anywhere NEAR the bathroom in his undies, positive reinforcement, negative reinforcement, stool softeners & potty prison, emotionless changing of undies, you name it. I'm so fed up with this. He has been peepee trained for about 9 months but will not poop in the potty. I have a 5 week old baby now with colic and I'm EXHAUSTED. I'm sick and tired of sliding his shit underwear down his legs and dumping poop in the toilet and reminding him next time let's poop in the potty. I'm getting to the point where I want to paddle his ass the next time he shits his pants. This kid knows what he's doing. This is a control thing and I do not want any part of it anymore. I have no idea what to do but I'm getting close to wanting to strangle him.I need Prozac. Why did I have kids?Edit: While I was posting this he took a huge baseball size shit in his underwear. I don't think I have the capability to be a good mom anymore. My husband just came home to me sobbing on the couch after changing him again. via /r/Parenting http://ift.tt/2tRgIt2