My Apple ID email is already in use
I’m old and technically challenged. I freaked out in June when creeps got into my phone because I fell for a phishing scam and let them in. I didn’t want anything to do with that phone anymore. Got an iPhone 12 mini and made stupid mistake of changing the AppleID but changed everything I could over to Google and using the prior gmail account only. Today I found out I can change the Apple ID so I did. It was simple. But then it said that email was already in use. Yes, on my old phone and my netbook. What can I do???
[Re-Titled by Moderator]