HELP - IOS 15.1 update on iPhone 13 - cannot use Wi-Fi or data or load apps

I updated to ios 15.1 this morning on my iPhone 13 and iPod touch. My iPhone 13 now doesn’t load anything on Wi-Fi or on my 4G/5G data. I cannot use apps that need internet as it doesn’t load and I am connected to Wi-Fi although on some Wi-Fi areas it says I am on Wi-Fi but no Wi-Fi bars appear and it says I am but nothing load anything. It was fine last night on the old software and now it’s just not working. I have reset my network settings and nothing, forget my Wi-Fi and added again and nothing and I have even hard reset my IPhone and nothing, it’s still the same. Now I have updated my iPod touch at the same time and that works perfectly, everything’s loads straight away. So it’s just my iPhone 13 with the problem. Even writing this on my iPad as I can’t get the website to load on my iPhone 13. Is Amy one else having these problems as I rely on my iPhone for work as I have no Wi-Fi at work and now all I can do on the iPhone is call people on it. Please can someone help fix it or get another update to fix it. I have loads of hospital appointments this month and in desperate need of it fixing. please please help.