Problems after 2.2.0 root patch

Mac stays like this and wont boot after the root patch update on my iMac10,1 late 2009, which had MacOS big sur installed. Ive tried a nvram reset, also tried to boot into safe mode by pressing shift on the bootefi and machd with no success, does anyone know a fix for this?

(Also what would be the best unsupported macos for my late 2009 imac10,1, its upgraded to an ssd and 8gb of ram, kinda scared to update is further)