Trouble with connecting phone number to Apple ID

Hi everyone! recently bought my first MacBook. I was very excited to use its full capabilities but it turned out that I can't call and text from it:( I found out that I need to connect my number to my Apple ID account and I am currently struggling with it. It says that my phone number is connected to another account. I've previously had 2 others Apple IDs (new phone new ID). I logged in every account and my phone number wasn't connected with any of them. But to my surprise- when I try, it only connects to my very first Apple ID. Of course I disconnected it and still- "I can't connect my number because it is connected to another Apple ID". I browsed the whole apple website, received 3843274572 messages from them and asked google a million questions.

I will be grateful for every suggestion:(

Someone pleaseee help me:)