Just want to make sure I understand the situation:
Sounds like you are using a roaming profile. Although it is loaded on the server, it is downloaded to your computer everytime you log on.
If this is infact the case one of twothings (or a combo of both) is causing the logjam. Three potential space hogs that are downloaded as part of your profile are your My Documents folder, files on your desktop, and your Outlook.pst file.
The outlook.pst file is the repository for everything having to do with your email account - contacts, saved email, deleted items folder, etc. If you have a lot of saved email, you may want to get rid of some of the older stuff. Set the deleted items folder to empty when you close Outlook if it's not already set that way.
If you have many files (especially large ones) either on your desktop or in your My Documents folder, I would think about archiving them, getting rid of them, or moving them to a shared file on the server.
Another issue that bears looking into is why you have so little free space left. You might want to consider getting a larger hard drive.