How lucky you are to have such a big wonderful space. Did you loose your pretty furniture too. If you like green, I would go with a softer, paler grey green, a new neutral, and I love pale yellow to brighten place up. Take a deep breath and start with color on walls, flooring, and lighting. Then what furniture you have and what you need. As I have 8 sq feet if space and things here and there, I would LOVE to be able to have that space. . Our vet has an almost new office and I would love a finished cement floor like he has, hard to do in a double wide. Let us see it as you work, and don't forget to look at the thread here on organizing a sewing room/space.