We all dream for many different reasons, and anxiety in dreams is very common. Dreaming is our unconscious mind resolving different inner conflicts.
In popular dream analysis theory, people in our dreams represent different parts of ourselves. An older brother, or a mother or father for instance, often symbolize a stronger part of our psyche, a fighter, while a child or younger sibling can represent a more sensitive part. Also, every space has some symbolic meaning - a cave is usually magical place, connected to our earliest childhood memories, while a cellar or prison is a place where we lock away those fears and emotions that we do not dare confront.
All these symbols are of course dependent on our own relation to them; for a lot of people a forest is a place of harmony, a mysterious place, but for someone with bad experiences in a forest it might mean something completely different.
So to analyze your dream accurately without knowing you is of course impossible. Especially without knowing what relationship you have to your husband or his sister. But the second dream seems quite obvious at first glance; you feel that you have some unresolved issue with your husband - can be very small - which your unconscious mind feels should be settled. Otherwise it will become a tiger that may hurt you both.
Running away is not a sign of weakness that you need to worry about. It is just your consciousness trying to avoid dealing with these uneasy questions.
I hope this answered something. If you are interested in reading more about common dreams and metaphors, I highly recommend Clarissa Pinkola Estés' book "Women who run with the Wolves" (1992).
Thinking a bit more about it, the tiger in the cage may also represent your own anger and frustration. Perhaps you fear that if you let your anger free, you might hurt your husband, so you keep it literally "caged up". However, neither of these options is ideal; your unconscious mind is telling you that you must confront the tiger and tame it.
The symbolic meaning of the kidnapping and stripping I still need to think about. Perhaps it is a fear of losing control, of losing your "defenses". This would correlate well with the image of the tiger set free.
These are very common themes in dream theory. You do NOT have to be a neurotic control-freak to dream about these things. :)