Pretty sure I have GAD as well as HA. HA is, as others say, the most prominent, but I constantly get worrying images flooding my mind - worse case scenarios, awful stuff you hear on the news. It's a wonder I leave my house half the time. I find myself picturing these awful, awful things happening to me or people I love. It's kind of soul-destroying, after a while, which is why you have to learn to fight back.
I am learning to deal with it slowly. Recognising that a worry has entered my mind is the first step, the next is to ground yourself in the present, usually through your senses - touch, taste, smell and so on. I think about what my senses are picking up on. That clears my mind (though it is difficult and requires a great deal of effort to do it successfully). The worry is likely to return, either very quickly or in a couple of hours, etc., in which case I acknowledge it as a worry once more and go back to grounding myself in the present. If you practise meditation, this will become easier. The point is not to chase the worry and react to it emotionally. Again, this is extremely hard, especially for those of us with severe and prolonged anxiety, but if you keep practising it you will start to see a difference. On a practical note, I also take evening primrose capsules every day as 90% of my anxiety issues are menstrual related and they do help to combat it somewhat.