Yeah, your experiencing a lot of hypnagogic imagery. That stuff is pretty fascinating. I usually wake up from those too. When are you doing it?
If your trying to do it when you first fall asleep, you may want to try it after sleeping for a few hours first. Then you will have a better chance of getting more fully into the dream. And yeah, you do have to try and stay calm. easier said than done though I know.

Welcome to Dream Views!