Need Desperate Help!!

This has been frustrating me for a while now. Changing emails. I have an account set to an email and I want to change the email the account is set to. But I cannot do it. I looked at many guides and followed them but nothing. So, before I went into game I clicked on STS Nexus. Then I go into My Account but there is no Modify account button. What is this? Does anyone else have this problem? Or is it just me. (My email is gmail btw). Please help!

You cant modify account on gmail,its happened to me too...

Awwww :(((