Question

they've been through... very, very different and complicated stages of 'love' throughout the years, I'd say. Law saw Jesse as everything he wanted to be, everything he could never be, and then as everything he wanted to have and could never have. He was obsessed, envious, jealous, angry, and in love with Jesse all at once. He had wanted to stand on equal foot with Jesse, once; only coming to realize through Moritat that his fucked up childhood had made for an equally fucked up adulthood where, in the end, he needed someone who's not an emotional mess like him - Jesse, obviously - to take control for him.
I think that during the early years of their relationship Jesse did love him, just... not in the way a lover does. More like pitying kind of love you feel for a puppy, something of a nature that's lesser than yours - but love, still. After going through Moritat, I think Jesse's love for Law evolved from 'this pitiful thing needs my love for my love, and I'm mighty enough to give it' - as in, a feeling that existed mostly to feed his own ego - to him seeing the mess Law carried inside him in its fullness and realizing it wasn't a mere gesture of kindness, loving him; it wasn't something to hand out carelessly, but something to nurture, to act upon, to actually invest his own heart in. no more 'he needs my love for my love', but 'he needs this specific kind of love that only exists when there's two to make it whole'.
still not the healthiest take on love all things considered, but Moritat was never about the taking the healthier path anyway. Law and Jesse are both flawed as hell, and if this were any other story they would probably stay away from each other and work on their issues by themselves, or with other people that not each other. as it is, they acknowledge their personal flaws and the flaws in their relationship and choose not to change - at least not fundamentally; sure, there's improvement in their characters, by themselves and together; it's just an improvement that doesn't push beyond what they're used to - but to accommodate and accept. that's what I took from it, at least.

Thanks. It just is too SAD.

This deserves top comment. what a brilliant analyse and really correct