I need to change my Apple ID to my current email address but whe I try to change it it says that email is unavailable.

Are you using this procedure to change the e-mail used in your ID? Change your Apple ID - Apple Support

Apple hasn’t published any guidance for using an address again. Normally, if your e-mail address was associated with an ID in any way, for example as a Notification email address or a Rescue e-mail address, then it can't be reused with another Apple ID for approximately one year. I have also seen posts that stated Apple told them there was a 30 day waiting period before the address could be used again.  You will need to get another e-mail address to use as your Apple ID or you can try waiting 30 days to see if that works.