I have a skin-coloured bra that I wear for semi-transparent clothes - you don't really notice them. The one I have is a push up bra, but a T-Shirt bra would probably work well too. Also for my really sheer mesh tops which are too obvious for a straight-up bra, I wear a bustier crop top (something like this: ) underneath/over the top of the shirt and it usually looks pretty nice.
1). do not get mad if guys look. 2). Be proud of what you have. 3). Do not be mad if i want a pic.. 4). you can wear a vest over it.
You have a number of choices. 1) as anonymous says wear a Bandeau. 2) wear a bikini top and just let it show. 3) Wear something skin coloured but this will get more looks.
Your could wear a flesh colored bra, a bralette, a bandeau, a tight-fitting cami, or a sports bra.
give it away to someone who will wear it more often then you would.
Wear a bralette
The easiest thing would be to return the top and exchange it for a larger size in a thicker material.
Try wearing a bandeau underneath!