Sometimes my daughter will spell out random combinations of letters and then ask me what word they spell. Usually it is nonsense. I imagine this is similar to what happens when you "come up with" a name and then try to find a meaning for it. Essex means something as a place name, but Essyx is not a name and means nothing. Sorry.
As for Trinity, I think it's kind of biting off a big chunk to name a child after all three persons of the Christian Godhead, but at least it means something, so, okay.
People will probably be more polite once your child is born and named, but what they are saying to your face now is what they'll be saying behind your back and your child's for the rest of her life. So, too bad for your kid, I would think, but she's yours, so you can name her what you want.
(Yeah, probably MUD. Dude.)