Hello, sorry for not bringing the answer, I just happen to have the exact same problem...
Affinity Photo just shuts down randomly every 5-10 minutes, sometimes it takes longer... and I've got to save my progress every minute or so because I don't know what causes the bug nor when it'll happen.
It started since the Affinity Photo latest version I think, I'm on Win10 Home also (up to date). So right now I'm moving on to a previous build 1.9.1 (hopefully that one was still saved in my Download folder, since I can't get access to older builds otherwise...) and hope that it'll help me get my work done quicker 😊 (I'll keep you informed if it works for me)
At first, I thought this was an issue with allocated RAM (the number were above my total RAM, which is 6 GB, I lowered it to 4 GB maximum), it seemed to work fine for one day or two, but the issue went back. Also, note that I deactivated hardware acceleration because my graphics card is a potato. Aside for that, feel free to ask me other questions !
My specs:
Windows 10 Home 64bits
Processor : i5-4670K CPU @ 3.40GHz 3.40 GHz
Memory : 6 GB
Graphics : Radeon R9 200 series
Affinity Photo : 1.9.2
Thanks for reading ! Best regards.