J.P.
My son is 3 1\2 now and I went through the same thing. Like you I tried everything until i ran into this lady and she suggested letting him run around the house without a diaper or under wear on, just a long shirt. I waited a few days and finally decided to give it a try and lo and behold he went poo in the potty, a week later he was doing both in the potty. As far as the getting through the night I had to cut off all liquids an hour before his bed time and not put the diaper on because when I would put the diaper on it seemed like we would go back in steps. They make little bed covers that absorb liquid and that was something I invested in. My son has been potty trained for months now but he still has an occasional accident so it was a good investment and it saves on a ton of laundry. It can be stressful and seem like a lot of work, be patient and strong. It will all come together for you.