Today I did these in my room..which isn't a big space...Did some arm exercises w/ dumbells. I also got on the floor (you could probably do this between the beds) and did some pushups (the easy kind, lol) as well as some crunches.
You could also stand sideways and do jumping jacks. Here is a video of chair exercises that you could do if you can fit a chair in your room or on the edge of the bed.
http://www.youtube.com/watch?v=BRWfzMTjOj4
If you're finding it really difficult perhaps you can try to do some exercises outside like walking/ jogging.
Good luck!!!