Guardianship
I’m sorry to hear about your situation and want to reassure you that God only puts those people in such big trials that He already knows have the capacity to deal with in the best possible manner. Islam doesn’t provide any guidelines for guardianship in case of death of both parents. Instead it asks the members of the society to step forward and help in such situations according to their means. It might be advisable that you make arrangements in advance with the family members that you trust, should such an unfortunate event occurs. There will also be certain legal procedures that a lawyer can help you with.