Kerryanne,
I think the wise thing is to see a doctor, just to be on the safe side. But to also take note that you experienced similar sensations during panic attacks, and that the likelihood is that it could be this; and also some other people say they experience the same sensations during anxiety. But I am not a doctor and since I suppose you aren't either, then I think to explore all possibilites if you are unsure.
Other than that, I know that it must be freaky for you, and that saying 'don't worry' probably won't help much. ...but I also worry sometimes about what I am going through. I read some 'expert opinions' who seem to make-out that what I may have is really, really awful; and then there are one or two opinions, like that of a psychologist who experienced social anxiety and the recovery from it. She describes the symptoms, thoughts and feelings so vividly and yet, unlike others, takes the air out of the balloon, making the problem seem less big and horrible. She even wrote: "You can have a problem, or you can have a really awful horrible problem" ...and I notice that reading her advice makes me feel better and good, whilst reading that of others makes me feel 5 times worse.
...and one way or another, anxiety is based on worrying and fearing too much. So it makes sense to simply believe that there IS an answer and a way and that for the time being we will feel confused and overwhelmed, but that when we understand what to do the problem becomes manageable and likewise smaller.
So, treat people's advice with a grain of salt. Some people also have a habit of making problems feel and appear bigger. But if you think about it, a person with the solution always does the opposite.
