By the way Dave rants you know he's scared.
You nod, you have nothing to say for yourself, nothing to say on subject. You have to tell him why eventually, there's no avoiding it. He's going to need to know because he wants to help you. He needs to help you, and you know that more than you want to admit. He really cares for you, you see that, and you never told him what's been going on in your life when he told you everything that went on in his. You see it as betrayal of your boyfriend and your best friend, and he should too, yet he's sitting here mumbling that you're going to get better. You want to believe him, you really do, because you know how much time and effort he'll put into it, but once the cutting starts it's hard to stop it. He knows that all too well, which is probably why he's so determined. Why he might lose his job. Why he'll neglect his friends. Why his marks in school will go down. Why he won't sleep. Why he won't eat. He wont do anything until you're better.
You touch your hand lightly to his cheek and he stares at you, startled. You must of broke his train of thought. He sighs, leans into your hand. You can tell he closes his eyes behind his shades, stressed, worried, scared. It's your fault. You're causing him this stress, worry, fear. You don't know what to do, how to relive him, so you simply murmur "Everything's going to be okay, Dave." You know by the way he bites his bottom lip he doesn't believe you. He simply can't. It's what Dirk told him. Then he cut again, he did it again, went to the hospital again, and now he's okay. But you're not Dirk, you're not strong, you can't handle this. He knows it, you don't want him too, but he does.
"and what if it wont be, Karkat? What if I actually lose you? What will I do then, huh?" You bite your bottom lip. He's right, as always. You smile slightly, trying to reassure him. You need him to at least think everything's going to be fine. If he thinks that, maybe it'll convince you also, and maybe, just maybe, you can stop. You will stop. You just need his help.
"Don't worry, Dave, I'm not going anywhere.* You tell him, pulling him into a hug. He reacts instantly, wrapping his arms around you, his face already buried in your neck. You rock him gently from side-to-side, and you can't tell whether or not you're comforting yourself more than you are him, but you could care less. You're still here, you're still in his arms, you still love each other, and you're both determined to get through this. To push past the scars. Because you will. You know it, he knows it.
Because you love him.