@Caves, Thank you for your heart felt sharing. So sorry for your dad's so brief time with you.
By chance, have you done your DNA test yet? It is not that expensive to get started. You will find lots of people who are related to you.
Have you put your aunt's maiden name into your search bar? Do you know where she used to go to school, she could be on an alumni list on FB. Do you know where she grew up? She again could be on a home town group on FB.