Changing your name won't repair your credit score.
And it is illegal to change your name for the purpose of fraud.
However, you are legally allowed to call yourself whatever you like. It is very simple to revert to your maiden name:
"To get all her documents and records changed, she will usually be required to produce her decree absolute certificate and her marriage certificate (a marriage certificate shows a woman's name before marriage). If you do not have either of these documents to hand, you may find it more convenient to execute a change of name by Deed Poll"
http://www.weddingguideuk.com/articles/legal/c hangingnamegeneral.asp