Regardless of the assertion of any negative state that seeks to convince you otherwise (using its painful presence within you as "proof" that the prison you're locked within will stand until the end of time), apply this one great truth:
All self-punishing states are "lies." They must break down if they don't succeed in breaking down your willingness to test their reality. How do you conduct such a test? You learn to look at their presence within you with the quiet understanding that, in reality, nothing in life is fixed. All things change. Everything passes. This is truth. Knowing this to be true is power over what holds us captive.
On the other hand, according to another great truth, everything in life tends to become more of what it is, so that the only thing "fixed" in us are those parts of our presently unenlightened nature that convince us to resist life's natural changes. As this fear-filled, downward-trending nature tricks us into accepting its conclusions, they become the same as our captivity. We unconsciously accept the limited and painful life this alliance-in-the-dark produces. We can do better!
Real self-change begins with seeing that real life is change itself. This means there is no condition that can hold you captive without your unconscious cooperation. Withdraw it. Wake up. Walk out of yourself by changing how you see what you call your life. Realize that while the contents of your life may come and go, turn dark, or suddenly seem delightful, regardless, these things will pass. Resting in the awareness of this truth while working to stand upon its higher ground, you come upon the life within you whose nature is the unchanging witness of these movements. This self dwells outside of change, even as all that changes moves through it.