my son was ADHD/ADD so his story is a bit different, but he couldnt focus on going to sleep. He was ALWAYS wound up tight. I would take a drop of lavender and drop it on the back of his hand. I would ask him to take deep breathes, and breathe it in till the odor went away. it gave him something to do. it caused him to breathe deep and mimic sleep, and it worked a long time till he discovered monsters under his bed. I make a "monster away" spray. I got an unused spray bottle, used a few drops of lavender, vanilla, and a lot of water. I put sparkles in the water with some gold stars that I knew would not clog the sprayer. Before bed we would spray the room for monster control. I told him a super secret story about a scientist who made the monster spray and got in trouble with his bosses who were in allegiance with the monsters. After he made the spray in secret and the monster removal team of the government found out he received all kinds of awards and each child could now sleep safely at night. Then I plopped lavender on the back of his hand and asked him to keep smelling it till it went away and it too would help keep the monsters at bay.
it worked about 90% of the time. I told him if he woke in the middle of the night and was afraid, just keep sniffing and before you know it you will be back in dream land.
Its safe, non toxic, lavender triggers the brain to rest, the story helps calm and turns on the story teller part of the brain that dreams create stories with.
As far as potty my son never wanted a diaper on him, so he was easy to train at a young age, but he didnt have your childs issues. Good luck, its a struggle.