imessage not working after travel

I've found similar questions here by searching but the answers/solutions haven't worked for me.

I've deleted the e-sim I used overseas but the imessage and face time green slide buttons in my settings are 'greyed out/pale green' meaning I am unable to turn them back on. My icloud/apple ID under settings is also unable to be clicked on/greyed out. I have a feeling I may be signed out but cannot work out how to sign in. I still have all of my apps and info etc on the iphone though. Does anyone have any ideas please? I've restarted the phone and that hasn't helped.