No need to be sorry, you have done the right thing posting here.
I totally understand why you feel like this, and I hope by reaching out people will come along with lots of good suggestions. You have so much to be proud of and I hope you know that.
One thing that occurred to me is about your aunt. How old is she? I remember how vague my mother was as she got older, and now have friends who are in their 70s and 80s who also seem to now have a vague grasp of things where previously they were very sharp.
Sadly a few are not the same vibrant people they used to be, and I'm wondering if that could also be the case with your aunt? Maybe she really did intend to be there for you now, providing emotional and family support, with long stays in Canada etc, but she has forgotten, or hasn't got the energy to make those sort of plans any more? If that is the case could that understanding help how you feel now?
You have suffered huge losses, and I think you are now feeling the loss of the support of your aunt, who though distant, you felt at the time did appreciate the huge sacrifices you have made.
Have you considered finding a bereavement therapist to help you process all this grief and loss? It could support you through this transition period as you look for ways to grow your own, independent life, free of resentment and eager to build a bright future.
You are young with so much ahead of you. Good luck. x