It sounds like you were both very young and both went through immense stress and pain. I wouldn't give either of you any kind of negative label, I would just observe that it is tough to keep a young-in-age, young-in-years-together relationship going through the kind of whirlwinds you both endured.

My advice is to focus on your studies and work, and maybe running if you feel yourself called to that. I think you were wise to sell the car. If it is meant to be, you two will find your ways back to each other in time.

You mentioned closure. I myself don't believe in that term. You are grieving, and grief doesn't just close. What I think will happen is that you will come to be able to bear pain more readily and so in that sense it will lessen, it will be integrated into your life and easier to carry. My father died over 20 years ago. I don't feel that searing pain of grief, I live a reasonable life, but I do still miss him. I would never say that I have had closure with regard to him, and I don't expect to ever be able to.