Thanks for your post and welcome to the forums. It's great having you on board with us in the Community.
I'm sorry to hear that your phone isn't working. You've mentioned it's been showing EE signal and this has now stopped. Have you changed anything at all such as the device or have you recently had a new SIM card?
When manually searching for the network in your settings, does this allow you to connect to it?
Can you try putting your SIM card in another phone? Please let us know if this gives a signal or if you have the same issue.