Please dont update.....it has made my phone useless.....internet connectivity goes off intermittently, phone hangs when memory card Is installed....apps like whatsapp/instagram crash like crazy

I am facing a major issue after update. my phone ui keeps crashing (opening phone/settings/menu etc.) this stops if I remove the memory card. based on support over chat, I was asked to "Reset all settings". this worked for a day but as soon as I rest...