Can someone tell me what they think about this dream I had?

Your intuition that this imagery pertains to family troubles is right on target. The roller coaster is an emotional roller coaster. Everyone in the family is secure in the coaster except you, and you have a harder time holding on than they do. They are riding through the situation a little better than you are. That they are all there with you, suggests that you are all "along through the ride", and suggests family unity through the "ups and downs" of it all. The dog suggests a supportive friend who is helping you through. In the end, you make it through the hard time on the roller coaster, you have a harder time holding on through the turmoil, but you ultimately will arrive safely on the other end of it. The cloth in the dog's mouth suggests a bit of wisdom or support which has been offered to you and is helping you through it. The color of the cloth may offer further insight as to what your friend said to you. The cloth is located in the mouth, which suggests communication, a verbal offering of some kind. A dog is man's best friend, and in this imagery suggests a friend. You take the cloth laughing and feeling better. Look up colors in different dream dictionaries for further thoughts to reflect on.