"Deus solus me iudicere potest" is a possibility. Word for word, that translates literally as "God alone me to judge can." (Remember Latin grammar and word order are different from English.)
I would certainly advise you to check that out before committing it indelibly to your skin! May I suggest that you approach the Classics teacher at your local secondary school - if it has one nowadays - or the local Catholic priest. Good luck.
Incidentally, after I'd entered the answer above, I went to the web-site recommended by Zen. Believe me...the translation it offers is nonsense! It even includes the English word 'can', for goodness' sake!
(That is not a criticism of you, Zen.)
More concise would be 'iudicium meum est Dei' of 'iudicium meum [or 'mei'] est Deo'. For future translations into and out of Latin it is worth trying a professional site, like Classical Turns (www.classicalturns.com).