Downgrading from iOS 26 to iOS 18 without computer or macbook.

Hello, Apple Users. Please help

me. I have an iPhone 13 and I tried updating my iPhone to iOS 26 because my cousin told me to update because it is cool and pretty. I know that it is my fault for not reading the pro’s and con’s of the developer beta. It is okay but it is just so laggy and my phone is overheating and my battery drains so fast. Again, if I have to wait until Septemper, please tell me. Also, please tell me if I have other options. Again, I don’t have a computer, laptop and macbook. I only have my iPad A16. Thank you very much, y’all.