First of all, congratulations! That's so exciting!
I've done some searching on some high street websites and I've found Miss Selfrige has the best range of dresses and at a reasonable price. They offer some really glam dresses and some really low key ones that could be easily styled up. You say you're the same size as me, so i wanted to keep that in mind and choose dresses i would wear myself. Each one could be worn with tights, a cardi or a jacket to maybe cover the bits you don't like it, they could all be worn with black shoes so you don't have to worry about having to find the same colour shoes to match the dress. I wanted to give you some splashes of colour so you stand out, but also pick a couple of LBDs if you're not feeling the colour! I've mostly picked dresses with waist details, for me that's my smallest part and can easily control your curves. I really hope I've given you some ideas and you manage to find the perfect dress for your special party!
Champagne 1 Shoulder Dress - £45
Red Tipped 1 Shoulder Dress - £36
Petite Embellished 1 Shoulder - £42
Rust Pintuck Dress - £32
Black Embellished Dress - £40
Petites Metallic Plisse Dress - £40
Camel Drape Bubble Dress - £40
Petites Blue Pintuck Dress - £32