Iphone getting locked

My Apple ID (ganesanmanju@yahoo.com) is constantly getting locked. For the last 20 days, it is locked more than 5 times and i don't know what to do.

It rendered my phone useless for an entire day because I put my password in too many times with the account being locked. Even though it was the correct password, it still just popped up on my screen to type in the password and then unlock and reset password etc in loop.

I am sure someone is deliberately trying to access my details and ended up without guessing the correct password and hence locked by Apple as Security.

I tried to use 2 ways verification, but that too didn’t give the expected result.

I am a FAN of all Apple products including TV & is it happening due to the usage of multi device using the same id?

Please address the solution.

Thanks