I think this is about a lost relationship. He's distraught and having suicide-like thoughts, or using suicide imagery as an metaphor for the relationship. "Skinny Love" is the relationship wasting away- wanting to pour salt on the relationship because salt has preserving properties on meat, etc. The sink of blood and crushed veneer might be him breaking the sink and cutting himself out of anger, frustration or angst or even cutting himself intentionally because of the pain. He wants the "ropes" of the relationship cut because he doesn't want to be caught in this pain; and he's saying that's a tall order, because it is impossible for him to forget. He's saying I told you to be "patient, fine, balanced kind" about the relationship. Why couldn't they both have been these things for each other? In the morning when he's with her, it will be a different kind, she'll be holding all the fines; another morbid suicide-like metaphor. He's gone to her, he'll always be in her thoughts but almost haunting because it's partially (or wholly) her fault he's gone. "Suckle" on the hope, it's physically what a child would do- would only have strength for. He's suckling for any hope the relationship isn't over. "Sullen load is full, so slow on the split"- this relationship has/had a lot of baggage, so the break-up is slow and painful. "Now all your love is wasted, and then who the hell was I?"- evokes images of a couple painfully saying these things to each other in their last moments. "Who will love you, fight, fall far behind", perhaps frustrated questions to an ex of "I loved you more than anyone could, no one will have you now". Beautiful, beautiful song.