Have I got a phobia of sharks?

My Dad is in the navy, he has seen many sharks and as a child I was always asking about them. He bought me a shark book as I was fascinated by his tales and was always asking about what he had been up to but when he bought me the book I found that seeing sharks and reading about them really seemed to give me the shakes. I was eight when I got the book. Then he got me a tooth of a shark and I was quite wary of being around it and it's fair to say that it gave me the creeps. But that's not where my phobia started. Ever since I have watched a shark attack on T.V. I have had this terrible phobia, to the point where I refuse to go in deep water. Then I watched Jaws and became absolutely petrified of the fish. Even the word Jaws scares me and writing this is making my fingers tremble. When I was on holiday I thought a plastic cup that kept bobbing up on my back was the predator (and I was in the pool), I couldn't see what was touching me and went straight into panic mode after brushing away the idea it could be something else (like a floater or a ping swimming). I had a panic attack and it's fair to say nearly drowned. When I see pictures of sharks I shake, become breathless and dizzy and in some cases I have broke down in tears. I am really worried because I have to be forced to go into a pool whether on holiday or not and even get worried when I am in the bath or shower. I am in year nine, am I going insane? Or do I have a case of selachophobia, what can I do?