I read a lot of self help books, really tried to change my negative thought patterns that I had developed. I changed my diet to a healthier one, added more cardio (aerobic work seems to really help my mood), make sure I get good sleep every single night, and started to meditate daily.
None of it makes any dramatic change overnight, but it eventually helps. I am still not out of the woods yet, I have made small improvements here and there over the years, but I still deal with a lot of anxiety.
Part of what has helped me is not using it as a crutch. I have accepted that I have anxiety, but I don't let it define me.... I try and face my fears, and reinforce positive thinking habits. I have seen so many people constantly address their anxiety and let it rule their life. I try to make myself think that I won't let it beat me, that I will conquer it and not let it ruin my life. Over time these thoughts become more of a reality. Our brains are so powerful, our thoughts really do influence physical changes in our brains. Just like developing bad habits messes with your dopamine reward system, you can 'train' your brain to develop more calming neurotransmitters by doing whatever you can to eliminate anxious thoughts. Allowing yourself to relax and breath when thoughts get out of hand helps, as well as forcing your mind to focus on something positive when the anxiety hits you. Making a conscious effort to change a negative anxious thought to a calming one is not easy, but if you do it over and over constantly, it eventually becomes a 'good' habit and will begin to happen more naturally.
Its a tough road, but I think it can be overcome if you really work hard at it.