Awww - its really hard to want to sew and not have a place. Is there any way perhaps that you could get one of the fold down ironing boards so that you can have a place for your machine or perhaps a closet that could be turned into a mini sewing room?
I have seen the sweatshirt to jacket idea and my mom did several. They are easy, fun and very striking - lots of room for creativity!
Good luck............