Honestly I'd get rid of the vest altogether. A big part of Lolita is the elegance factor, and the vest just doesn't fit. The shirt is a good starting point as it's modest with cute detailing.
The reason your skirt is still droopy and sad is because I don't think it's the proper shape for a petticoat. And with the tulle and shape it's more fairy kei than gothic lolita.
There's no shame in asking for help and suggestions on your first couple of coords. Lolita is a very hard style to master. I think you'll have even better luck posting this in the EGL forum here.
The girls and guys that frequent it always have amazing suggestions and are really eager to help! Trust me, I lurk there all the time.
A bit of advice though is not to call it a "cosplay". It irks the community because to lolitas it's not a costume, it's a whole fashion subculture. Good luck pulling this together!