Another question: has anyone had the feeling when they are in a dream that they can't move? I want to force myself to roll over to the other side and something invisible holds me there. I noticed this happens mostly when it's cold.

Roll over on the other side IRL on in the dream? In the former case this seems to be a very good description of sleep paralysis[1], including the sensation of something invisible holding you immobile. (tl;dr for the wiki article: When you are asleep, you are paralyzed. Sleep paralysis happens when you are already paralyzed and not yet asleep, or still paralyzed and already awake.)

[1] https://en.wikipedia.org/wiki/Sleep_paralysis