To be honest, I think you're doing alright so far. Karkat took a long time to come to trust us and Dirk already s33ms to trust you. Being there for him emotionally might not be your strong suit, but you should at least try. If you think he's upset by his death, then bring it up. Not in a 'do you f33l x' way.
But in a 'I f33l x, and that's okay if you do or don't' way. Being a parent sometimes means you have to put aside your own faults. You have to let him know it's okay to f33l that way and okay to admit it.
filtered;
Being there for him emotionally might not be your strong suit, but you should at least try. If you think he's upset by his death, then bring it up. Not in a 'do you f33l x' way.
But in a 'I f33l x, and that's okay if you do or don't' way. Being a parent sometimes means you have to put aside your own faults. You have to let him know it's okay to f33l that way and okay to admit it.
Same for Dave.