I'd wait until the cold is gone, and then make another assessment. If you've been running a fever, that can really affect your ability to sleep, or at least sleep soundly (I know, because I ran a fever almost all of last week) . Also, cold medicines can sometimes have the opposite effect on people (I'm one of them), where it can make your mind almost hyperactive.

Also, since this is fairly new to you, your mind is probably working overtime trying to make sure you "do it right", and anticipating the wonderful experiences that you may encounter. After you have settled more into a routine about it, you may find that you are able to relax more easily, and put it out of your mind when you aren't trying to LD.