Ok, emergency fashion help needed. I've had my head in the sand
On the 28th (so you know, a week-and-a-half) it's my cousins wedding and I don't have a dress. DS is 14 weeks old and originally I was hoping I'd have lost a bit of weight and be able to squeeze into a dress I bought for a wedding at the beginning of the year. I didn't actually gain much when pregnant, was a 12-14 pre-preg and still able to fit my old trousers at 34 weeks (then I ballooned). I did drop quite quickly after birth but since then have not done well. I'm a size 16 (18 in some shops) and hate my current figure -bloated, wobbly belly and always had small boobs.
I know I need to do some dieting and exercise but in the short term I just need to find a dress! Smart wedding, need a proper posh frock but want one that is going to be soft and comfortable so it's easy for me to deal with DS - not too restrictive and nothing to scratch him. I'd like it to be a bit flattering. Budget: say £60-70 ideally but would stretch to £100 if it was really worth it. Go on someone, help!! (PS we're off to Eire on boxing day, so my last shopping day would be Christmas Eve, yes a week tomorrow ARRRGGGGHHHH). 
Vitals: 5'4" tall, broad back, small boobs, massive tum, arms and lower legs ok (chuncky thighs though). Can't do heals. God I sound hideous Thanks