Problems with Prozac!?- please help

Hi! Two Friday's ago I started taking fluoxetine (Prozac) 10mg once a day. I was plagued with severe nausea, discomfort in my stomach, weakness, anxiety, lightheadedness. Whenever I took the tablet I felt it's effects almost instantly, especially in my chest, it was that feeling of panic when you are told someone has died, that throbbing and it was constant. Anyway, I took it for exactly 7 days and the side effects worsened, it was also making my insomnia worse and I couldn't eat because of the nausea. So I stopped taking it on the 7th day as I was told that I would be doubling the dose. I have a phobia of vomiting, and when I feel nauseous the anxiety about being sick makes it worse, so it turns into a vicious cycle. So I had to stop taking it. I was also taking cyclizine, to stop me actually vomiting. Anyhow, it has been 2 weeks since I took Prozac and the constant nausea has subsided, but late at night it returns and I still have the discomfort in my stomach. I also keep getting this feeling and the only way I can describe is like being high, that dizzy, heart racing, and that feeling in your throat and a rush in my head, it comes and goes though. So I really need some advice because I'm starting to worry. My family have said because I'm small in frame, the drug might have hit me harder, but you know what family are like. But I'd really appreciate any advice on what to do. Any help would be massively appreciated! :)