Hey, I am sorry to hear about your grandfather and university. Please, accept my condolences.
They say life is something that happens, while people are busy making plans. But in the end, even the best plans crack sometimes just to test us and lead us towards a more rewarding path (long-term).
You need to make a space for yourself to grieve - grieve loss of the loved one, change in payment conditions of university. Give yourself a bit of time. Grieve genuinely and deeply - you can write a letter to your granddad with description what he meant for you and what you are thankful for, you can write the unsaid words you held on to or simply write a letter to your children describing him. I think it always helps in such situations to pay attention how his death affected other close people to him, try to be there for them and you can share your grief together, but don't get stuck in it. He wouldn't want this for all of you.
But sooner or later, you have to get up and face the new reality. If you managed to get into university and accumulate resources, you are capable of doing this again. Moreover, I would suggest fighting for yourself - look up grants, scholarships, crowdfunding opportunities. For sure you are not the only one, who is not happy with fee increase - unite with similar minded people and negotiate with the Dean's office. If they will realize that it's better to get less revenue then none at all, they may make some concessions. Another option - writing a letter to Dean's office what this opportunity means for you and how hard you worked to get there. Brainstorm other solutions.
Once you did everything that depends on you - plan your "worst case" scenario, if this doesn't work out: applying to different university, joining as a free listener in this one, maybe you could find uni where you get credits by working. Maybe this is a chance for you to look around as well - double check your choices, consider how you would spend your gap year - you don't have to go to necessarily go to uni to educate yourself (in the meantime of saving up for uni education next year) - find a mentor in the field you like (LinkedIn), pursue coursera/edx online courses, find influencers in your field and follow them.