my iphone 6 getting slower after update ios 11.2

After updating ios 11.2 my iPhone 6 becoming very very very slow it s better to use an java phone because to open the camera I need to stay about 1 min really very sad. Because we cannot upgrade to a new phone when New one is arrived because we are not working on apple company please look small people like us please we are begging on you solve this problem not only camera every app even the settings please come across this thanks for your valuable time