Hello,
First of all: thank you for your very detailed response 
You tell me that dreams are supposed to make me aware of things in the past, in the present, and in the future… However, I must not draw the conclusion that it is always the same type of situation that presents itself to me in my dreams. ???
That is to say, I have to leave and pack my things, I’m given very little time, and I’m afraid of forgetting something. I’ve been having this kind of dream for about ten years. It takes place in different locations, usually places where I’ve lived before. :-\
Does this dream reveal a fear of abandonment or something else? I am unable to grasp its meaning and make progress in a way that would stop my mind from sending me this alarm signal.
As long as I am dealing with a dream specialist, I would like you to also enlighten me on one point: as a child (from about 4 to 13 years old), I used to have frightening dreams involving extraterrestrials.
It’s silly to say, but I was terrified; it was the only thing that scared me. However, in my dreams, those beings never harmed me, yet I couldn’t shake that fear. Even today, I still think about it, and during the day I laugh about it. I mean during the day, because if I’m out at night, I think about it and I’m on guard, even though I know it’s stupid. Another detail: I can’t close my eyes when I’m in the shower, otherwise I feel a presence (non-human).
I know it sounds crazy. I’ve only mentioned it to a close friend once (he made fun of me) and to a therapist (who suggested hypnosis without really taking what I said seriously), but I haven’t gotten any answers to my questions.
I am reaching out to you to see if you could also shed some light on this matter. 
Thank you in advance,