Well I am an apple shaped size 16 and 5'5 so I feel like I know where you are coming from!
How old are you? I have to be honest, I never find much I like in debenhams and my mil keeps buying me gifts from there so it has put me off even more
. I work on a freelance basis so I am mostly at home with DD2(2), doing the school run and activities with DS(11) and DD1(9), I found the transition from work wardrobe to current wardrobe awkward to begin with but feel more comfortable now.
I bought a good pair of knee high leather boots and a large but 'me' bag.
A good coat is a must - with a hood!
I often wear jersey dresses (they are a god send!) with tights and boots (layered up with a cardi if cold); jeans, long sleeve top and cardigan with either converse style trainers or boots; slim leg jeans, vest top and wrap top over with boots.
For example today I wore dark denim straight leg jeans (MANGO) with a white vest top, THIS cardigan in grey, grey suede ankle boots and long beads. I was doing a bit of shopping, looked smart enough but so comfortable.
I make sure I wear make up and always do my hair, I moisturise, pain my nails and acessorise even if it is just wearing earings! These things make me feel smarter.
I shop in Zara, Mango, Next, H&M, M&S (indigo and limited collection), Dorothy Perkins, Warehouse, Oasis, Monsoon etc. John Lewis is ideal as so many under one roof.
For more special occasions I like Coast and Almost Famous (@ house of fraser)