I can get why Dan feels lonely, since he knows his beloved grandma will die (soon, likely and sadly). I can also get why he feels culprit, even if actually he has no guilty at all, because he's a responsible sweet person. But even with all of that, please author doesn't make him to forgive J too soon. Dan knows how true love is, thanks to his grandma. He should stick to that and do not be weak with J just because he's sad, angry, hated: he has deserved all of that. J needs to apologize and behave lovely, then apologize and behave lovely again, and again and again before deserving just a little bit of Dan's love.
I can get why Dan feels lonely, since he knows his beloved grandma will die (soon, likely and sadly). I can also get why he feels culprit, even if actually he has no guilty at all, because he's a responsible sweet person. But even with all of that, please author doesn't make him to forgive J too soon. Dan knows how true love is, thanks to his grandma. He should stick to that and do not be weak with J just because he's sad, angry, hated: he has deserved all of that. J needs to apologize and behave lovely, then apologize and behave lovely again, and again and again before deserving just a little bit of Dan's love.