Overthinking things, feeling restless and having a general lack of trust in yourself and your external environment can be an indication of Kidney Water imbalance.
The lesson of the Water element is to tune into your inner knowing, learning to trust your innate instincts, rather than reacting with the feeling of fear that stems from the mind. Becoming aware and present with your emotions, and of course not fearing them is a simple practice that can help to both manage or release them.