Depends on how badly you want it/how much ugly you are willing to put up with in that spot..
You could certainly nurse it back to health. Or you could discard it and try another.
Some folks never give up and others toss anything that annoys them- which are you?
:)

Might as well buy another, leave the live part, dig up the dead part, and plant the new next to the existing. Then, if that doesn't work, I'd suspect something wrong with the soil conditions. When did you buy it?

I was really counting on flowers this year, I'm getting married late July and right now every foot means a lot in terms of my flower budget...

They have a lot better looking ones in the stores still. I got it around mothers day, out was looking great. When I put it in the location there was a tree root that I did my best to get rid of. Could that be my issue? I let it wilt a little and the wilted part just never came back. I'm thinking it was my fault for not keeping it evenly moist until it was more established..

I would dig it up and pot it up and get a new one to replace it. That way if this one does start to liven up, you've still got it to use in another spot in your garden.

I did that w/ one of my strawberry vanilla hydrangeas I purchased this spring that had zero leaves on it still, and the garden center told me to keep the old one. I potted up the old one and now it has leaves sprouting on it like crazy.

Good luck and congrats on getting married :o)