If this is so it isn't for you.Donate it ,swap it,take it back and only wear what you feel good in.
What's wrong with it? Why do you feel weird?
You'll either get used to it or change outfits.
I'm not used to wearing dresses either. Sometimes, I do end up finding one or two that I end up comfortable in. :/
Don't wear it and get something different. If you feel weird then people will notice you are uncomfortable.
Honesty is always better plus if you act like you like it now tomorrow you could possibly have another dress just like it tomorrow. Always be honest you can do that without being hurtful.