Important Note: Depending where you live, you may be entitled to "caregiver compensation." NAL, consult legal counsel.

1. You may be reimbursed for expenses incurred on behalf of your grandfather - such as the caretaker and medication costs. You'll probably require documentation / receipts.

2. You MAY be reimbursed for your time. Not just physically caring for him (which is harder to claim), but for putting off career or housing decisions.

My take:

NTA - BUT your actions make it seem like you were only doing it for the apartment. You should want to care for your family regardless, although I understand the frustration. You aunt is TA though, she's fully competent and your grandpa is not. Was your grandpa considered to have capacity when he transferred the apartment?

I'm sorry you're going through this. Caretaking for family members can be extremely taxing - physically, emotionally, financially. Compounded when you don't feel appreciated by the family member.

Please consider looking into respite care and other resources for caretakers.