No don't go to A&E until you've given a correction dose and see if that works, drink a lot of water, that helps too. If it doesn't come down at all or rises more in 90 mins/2 hours, then call out of hours.
Hi. Glad you got some help. What insulin regime are you on? If you are on mixed do ask to be changed to Basal/Bolus which gives better control. Do seek ongoing guidance from your DN with regard to getting the insulins right and doing carb-counting if your aren't already.