My fucking phone updated to 18 I hate it!

I was so desperately trying to avoid this from happening but it did my phone updated to the 18 version this morning when I was sleeping. I hate it so much it causes me mental stress. I tried asking for advice on how to revert it but they said apple doesn’t sign 17 anymore and my only choice is to comply but how can I comply with something I fucking despise!! I hate this so much…