I wear a size 16 (14 in some stores). Wearing cute clothes does make me feel better about how I look. But of course, being a 10 or a 12 would be even better! Wearing big clothes, only makes you look bigger! Especially t-shirts!!!!! Finding nice things that fit and are cut well can not only make you look good but feel better.
I invested in some basics that fit well. These are my favorites:
Jeans: Gap Original Bootcut or Gap Straight Ultra Low Rise Boot Cut, they both go up to size 20.
Black Pants: INC (Macys, they have a regular line and woman's), Gap Modern Fit Flare, NY&Company
White Shirt: Brooks Brothers, Gap, Old Navy, JCrew
Blazers: Old Navy, Gap.
Flare skirts are in this season and are great for covering up stomachs! I have a plain white one (Style from Macys) and a Pink one (NY&Company), and then some print ones from Old Navy. For casual wear, I'll pair them with a tank top or a t shirt and for work, a sweater or a tank and a cardigan. I also love to layer- tank tops under t shirts (girl sized!) or long sleeve shirts, v necks, button down shirts, etc. Blazers with tops underneath are nice with dress pants or jeans. I know having a large chest is often a big hindernce in buying clothes (I think the only reason I can shop at the gap is because I'm small chested!) but Lane Bryant's clothes and Target's woman lines are really cut well for a larger chest! Good luck