VBA to check if Data validation selections are not duplicated

I have drop down list in Column B on my Daily Chgs Tab. I would like to enter Some code that would check to see if once they choose a drop down that it is not duplicated or it was chosen before on any of the other Choices.

And if it has already been chosen to say please choose another you can not have duplicate entries.

Also can it be added that if within that range (b3:b60) has there been a maximum of 45 rows with data entered.

I have more Rows with choices that my destination sheet will allow so I would like to be able and alert the user that he has used all the rows available for input.