Can’t make changes to my site user denied access

Hi hope someone can help me or direct me to someone that can,

A year back I pre-paid Ryan Halls of ryanhalls.com to make me a website with my own domain name, using WordPress, and to maintain it for 2 years, and all was well. A few weeks back I had an email saying Ryan had died of cancer and I was on my own with my website as no one was taking over for him so no refund, no help etc. The guy who contacted me to tell me this isn’t answering my emails. I have minimal computer knowledge, but I was shown by Ryan how to update images and writing on my site. I went into my site recently to update some images and couldn’t as I was user denied (WordPress database error: [INSERT command denied to user). This hasn’t ever happended before. Can someone please tell me what to do so I can use my site again or direct me to someone that can help, thank you very much, Dan