Hi Jay:
Your reason is "Common usage". That's legalese for "all my friends call me this already, so I might as well make it legal".
In the US (I'll presume you're there), they are only concerned that you are trying to hide from debt by changing your name.
As long as you tell everybody you owe money to about this, there is no problem.
Also, there may be objections to you changing your name to something rude, obscene or with numbers in it.
I changed my name in court to Renate simply because I preferred it to my old name, transsexuality did not enter into it.