University can wait. My daughter is 30 and starting university. In fact, you are never too old. Wouldn't you rather be entering university being in a good place emotionally? Have you considered that waiting until you have the work done, and your mental health is under control would be setting yourself up for success? So my recommendation is that you accept your grandfather's support. My second recommendation is to remove yourself from the home situation with your mother. It is unhealthy.