I suggest you read everything again starting from the flashbacks.
Trust me, I reread it. IT WAS WORTH IT.
I haven't reread it yet, but I think it's like this. Jesse was a selfish asshole who was in love with Law, who he put through years of emotional pain & treated him like a lowly chewtoy & a slave, but despite the abuse, Law still loved him but wanted Jesse to understand what hell he'd put him through, so he created Moritat & switched much of their roles & personality traits so that Jesse would go through the same hell he put Law through, while Jesse was under the false impression that he himself had amnesia & was the one who created Moritat.
They both love each other thats why law created moritat to hide jesse condition. After law proposed moritat to jesse mother the accident happen to law parents but he didnt give any emotion for the accident and abandoned them so jesse get angry with law because of moritat. The first use of moritat is with the blonde maid but the issue spread and moritat was dumped. Because of issue jesse want to try moritat to forget everything for a day. After using moritat jesse recognized law sacrifice to be with him. Thats why law is in vr room dreaming that jesse will be with him. And then jesse came and tell him that it will become real that they will be together
I read it but i still don't really get it ?? ( despite it was so interesting (￣∇￣") )