My world got reset after I downgraded the version from 1.18 to 1.17.1

So I have an SMP with ALL of my friends, and we are on day 1070 and so the server just updated automatically today to 1.18, I wanted to go back to 1.17.1 since Optifine isn't ready and there aren't any plugins, I go back to 1.17.1, and the world is just POOFed, all the pets and entities including items/ items on item frames are still in the same place as they were before the reset. I have a lot of important stuff in there, I have and ENTIRE book written for a girl I like that is on the SMP for her birthday, I got items that are actually important for me IRL and I really want to know, if there is a way, I can get the world back, I don't have any backups, or nothing, I beg you please help meee

Yeah but is there somehow a way I could return it by any chance?