Hi there beautiful disaster.
That's definitely an interesting one.

First of all, it's perfectly normal to have fear in life, in fact sometimes it can be healthy and can help us to avoid danger. Nevertheless, this sounds to me like it may have something to do with losing control.
When we are vomiting it may seem that we don't have much control over our body, however the resulting feeling for many people after the act is one of relief.
How long have you had this fear?
What kind of situations trigger it, can you give an example?
Also you said that mother and grand mother have a tendency to panic. That's also very interesting, because we learn many behaviours from our parents, especially the not so good ones
From my experience with panic attacks I have found that behind the fear there was usually another deeper fear hiding out. For instance, I often get nervous in social situations, and may become very afraid to speak out. Later I find myself feeling quite lonely - which can be sort of like a vicious circle. However behind the social anxiety for me there is usually a fear of letting people get to know who i really am. That they may reject me, etc.
I know that this may not necessarily apply to your situation, however I'm just drawing a parallel. I would encourage you to look deeper into this, and see if you find some set of feelings or associations that surround this fear.
Very often just shedding light on our subconscious can help to get rid of the more obvious problems that we may be experiencing.
Anyway, hope that helps as a starting point, and welcome to eHealth!
Cheers
Daniel