regressing from potty training.

DS will be 4 on 12/6 is completely potty trained. Hes been completely potty trained for a year. The last 4-5 months DS regressed really badly. He would not even feel like going to the bathroom and just go in his pants. He was having sometimes 6-8 accidents/day. I was at my witts ends with the entire thing so I decided to put pull ups on him. I was sick of cleaning pee off of my furniture, floors, and doing peepee laundry daily.. Since he now wears the pull up he will just pee in the pull up and not even go potty at all.

WHAT DO I DO?!