Upgrade from 17.01.2 to snapshot

I lost everything, so there is no way to keep all my packages, settings, USB storage / swap / overlay.
How can I keep it?

For sure the packages are gone, you will need to reinstall them.

Did you check the preserve settings checkbox? If so, packages settings should have been saved, only packages themselves are discarded.

Other way to preserve settings is to make a backup of the settings, then restore these settings and reinstall the packages after. This way you don't need the preserve settings on upgrade.

Either way you will need to reinstall the packages manually or use scripts for that.

Or you can compile a personal firmware that contains the necessary packages built-in.