Need an outfit for a wedding, plus size and struggling

[NaraDeer]

I'm the biggest I've ever been and I'm really struggling trying to find something nice for a wedding I'm going to next month.
I need to cover my arms to past my elbows and I really don't think I'd be comfortable with even my calves being on show now. I have small boobs and very big waist and stomach.
So basically, I have no redeeming features to show off and I need something that will look half decent whilst I hide my entire body but at the same time I want something that won't be too hot in the July weather.

Any suggestions or shall I just go hide away forever now?

sorry I meant a not fitted jacket ^^

A huge thank you to everyone who has posted. I went shopping with all of your ideas and I think I've found an outfit, hurrah!
However, now I'm lost when it comes to what to wear with it

It's very simple, black fitted trousers, blush pink draped, floaty top and white blazer.
I need shoes and a bag. I have super wide feet and can not walk in anything but flats or VERY chunky heels, any suggestions?
I have some delicate white gold and pink morganite jewellery (ring, earrings and necklace) would that be ok or would a chunkier statement necklace be better?

Can you post a pic or links to pics of the outfit?

for this thread!