It's not going to be painful, it's going to be meh. If she dies, it's cheap tragedy. If she comes back after many years, it's cheap happiness.
The whole guilt trip is not that well described to be honnest. As someone who did a lot of shitty things as a teenager and young adult, and even a few years ago, I think you could really do a better job at explaining it.
But heh, it's not that bad either. A lot of interesting things are depicted.
I find little pleasure at reading it though, as I come here mostly for romance and so far it's not really packed with that.