Mindfulness Practice will help. But it is a practice. It takes time to learn. If you can find a mindfulness meditation class, it would really help.
Mindfulness helps you to center yourself in the "now moment". You'll start by learning to focus on your breath. You focus on your breathing and on a simple mantra. Something like - "Breathing in I know I am breathing in. Breathing out, I know I am breathing out" and you build from there. When negative thoughts or feelings appear, you acknowledge them without any judgment. You simple allow them to enter and exit your mind without any effort to control them. You focus on your breathing. The only real moment is the present.
I have been training with a student who learned from Thich Nhat Hanh. We are attending another retreat with him this summer. It has changed my life. You can google Thay (Thich Nhat Hanh) or Mindfulness Meditation and download apps to get you started. Here's just one example-
Affirming peace and wellness for you, OP.
http://www.lionsroar.com/mindful-living-thich-nhat-hanh-on-the-practice-of-mindfulness-march-2010/