Someone PLEASE help me!!! Crying ALL night! Please help me.

I've been crying all night! I'm getting married in 18 days, & my wedding gown that I had originally purchased from Macy's is way too big! I mean I could NOT take one step in the gown because it was a good 9 inches too long.
So, I took the gown to my own seamstress who almost fainted when she saw how huge it was. This would of course add to my $$$ that had to go into this dress. But it had to be done, so whatever. Now, I tried the gown on today & it just seriously doesn't have the same look as the original. I was in tears & my SIL said Get in the car, we're going to find you a new gown! So, we went to David's Bridal & found one that I really like! It would still have to be hemmed. It's not as sparklie as I'd like, but it fit & it was lighter. The Macy's gown was from the winter line & was so heavy. Then my SIL gave me a signed check & said, 'If you like that dress, then your brother & I will be happy to buy it for you.'

What should I do? With only 18 days to go, should I just stick to the original dress even though it does NOTHING for my figure & looks plain? I'm a size 6, but you'd NEVER tell by the way I look in the first gown because it's boxy & baggy.
Link to David's Bridal Dress