We instituted a calendar program when my son was about her age and having the same issue. We put up one of those big desk calendars on the wall and for each morning he got up dry, he got to put a sticker on the calendar. We set the first week dry to get a new car as a prize. Then the big one for the end of the month was a loft bed (long story on that). He remembered at the end of the month our promise about the bed and stayed dry for an entire month and has been ever since. I think he had 1 accident that first week and one later in the month when he was sick.
We had previously tried making him help change his sheets, he would help wash them (he started helping with laundry on his own when he was just over a year), on & on with different ideas & tricks, then I came up with this from someone else's suggestion regarding behavioral issues. Worked like a charm and he also learned about the days of the week, telling dates, and the passage of time in a calendar. It was a winner all around!
Hope this helps! I know how frustrating it can be. Our son potty-trained on his own just after 2yo, and spent almost a yr & 1/2 in pull-ups at night.