I can live with automatic IOS upgrades, because at the end of the day, my phone will still function, even if I lose all the apps. However, I lose my laptop ...

I can live with automatic IOS upgrades, because at the end of the day, my phone will still function, even if I lose all the apps. However, I lose my laptop ... I am screwed (I can't afford backups right now). I also have software that I paid rather a large amount of money for (back when I could afford it) that is incompatible with High Sierra and I cannot afford to upgrade the software. So, I'm kinda stuck between a rock and hard place here.