Living with my grandmother as a 30 year, how do I make my own life?

mmm1214

Hello, I am 30 years old and live with and care for my 90-year-old grandmother full-time while working as a high school counselor. Long story short, my mom is a narcissist and comes up with 100 excuses on why she can't help me. She lives about an hour away and visits 1-2x a week and only takes her out to lunch, never offers to pick up her prescription, chores, ect.. I moved in with my grandmother 8 years ago to attend graduate school before her dementia really set in. Gradually, I started to take over the bills, cleaning, ect. Due to bills, I can't afford my own apartment. My grandmother has been declining and I come home from work and go right into caregiving mode until I go to bed, and even then, in the middle of the night, sometimes she will need me.
Has anyone experienced a similar situation? How were you able to create your own life? I'm in therapy and I'm exercising and doing all the things to help my mindset, but I just feel really stuck and resentful at my mom and starting to at my grandmother for depending on me for everything. Are there any younger caregivers out there feeling similarly?