I helped my mrs get through severe anxiety, so bad she couldnt leave her bed at one stage.
First step is understanding anxiety, knowing why you are feeling a certain way goes a long way to overcoming it. If you understand how it works its a lot less scary.
This website was very helpful
Anxiety Attacks Read through it, my Mrs even joined up and said it was well worth it.
Another hurdle is those around you not understanding it and saying things like "You have no reason to feel this way just get over it". Anxiety is all about feeling certain ways for no reason, its not your fault. Direct friends and family to the above site to help them understand what you are going through and enable them to be a help as opposed to a hindrance. There is a section for non sufferers to read and be educated on it.
See a doctor, they will try a few different medications to manage and reduce the effects of anxiety. Some work, some dont, it depends on the individual. Just dont stop taking it because you think its not working, it can take a couple of weeks or more to start seeing results. Try and keep your mind occupied, sometimes this just isnt possible but keep reminding yourself that it wont be like this forever. You WILL get better if you seek help.
We found printing out all the symptoms of anxiety was helpful, whenever you feel off refer to it and knowing its anxiety and not your life ending is a big help. Just keep reminding yourself its a symptom, Im going to be OK. Anxiety can have many physical affects as well as mental which heightens the fear of whats happening to you. Again, understand it and how it works is a huge step forward.
I hope this helps.