No one can answer your question... because
- did you actually stream to YouTube? [not think it did, know it did]... Where you watching a preview? someone else comment/see your livestream? etc?
I ask as some people see green light in OBS Studio and assume (incorrectly) all is well... all that means is connection to streaming CDN server (YouTube in your case)... it does NOT mean YouTube was able to process your stream... for that [green light from OBS Studio entire stream] you'd have to check YouTube logs, and ask them. I'd check your corresponding OBS Studio log first though
Did you also locally record in addition to Stream? [I always do as a backup]
If YouTube doesn't have video, and you didn't locally record, then unless you routed stream through another service which did Record video for you, I'd assume video is lost... but many other considerations regarding setup, so can't be 100% sure
