What Causes Insomnia Along With Severe Depression?

I am an athlete that takes my physical training very seriously. I pay attention to my diet intensely and work out about 6 days a week. However I suffer from anxiety and have an extremely hard time falling asleep, getting deep sleep, and staying asleep. This usually results in me having a very difficult time recovering and having energy for the next day. Taking Xanax before bed seems to help me sleep and I feel very well rested when I wake up the next day. I am just concerned with whether or not taking Xanax before bed will have any bad physical affects that could slow down or deplete my performance and results. Will taking Xanax before I go to bed affect my performance and results?