I often have a dream of this huge place. I'm always terrified of the lower levels of the house/mansion. When i go down there in my dreams I don't feel safe, it's dark and I sense danger.

The upper levels are roomy and spacious. There are "doors" to different places.

my favorite place to visit is what seems to be some sort of body of water. There are animals everywhere. I'm always trying to catch/pet them. Through a hidden door I enter an unstable small house located in a huge tree. When I'm there I feel safe. I find little trinkets that seem familiar to me but I can't place why.

I constantly dream I'm falling to "different levels" in the dream...And it's weird. It's like the wind catches me and lets me land safely...

I read that a dream of a house represents your own mind....I just don't get it.

yes the house is you and its many rooms aspects of you.
You keep much of yourself hidden from the world because it feels safer for you..
Depending on the animals there could be various things you are wanting to embrace at the time. these very well could represent different kinds of people... in that case you want to pet them. You do want to get close to people but are afraid of being completely open.
You know that people can share emotionally with you, you love connecting to people in fact.. but still this doe leave you feeling vulnerable

People see you as being outgoing and willing to try thing, open to new ideas etc.. but you don't really feel that deep down as much as you would like to. You dont even admit to this to yourself..or it not something you consider a part of your identity.. you do fine without having to.

thanks that actually describes me extremely well