B..
Well, you found something that began to work, and stopped. He was opening up, and you went right back to the old way. What did you expect would happen? The only advice I can offer, is stop what isn't working...and do what looked to be working. Children are work, sometimes an overwhelming amount. And, then add a job to it. I get it, you feel like you don't have time. There are only so many hours a day. Well, find a way. As hard as it is, I don't know what else you can do. Sorry, but you can't expect what isn't working, to work. You know what will, so try everything you can to do that.
Have you seen a doctor for sensory issues? He needs to see one. This isn't something he will just learn to deal with, or grow out of. He needs help. 4 years is too long, to allow a child to struggle like this. It will not get any less stressful for you, to just let it continue.