I'm not sure about hypnotherapy in that I've never tried it.

Specific phobias such as yours with dogs are very very treatable. General fears are really common, I think they're only called phobias once the fear is changing your behaviour or restricting you in some way. Since this sounds like it is really starting to affect you negatively, I'd recommend that you see your GP and get a referral to a medicare registered psychologist who deals with anxiety. You'll get around 6 sessions that are claimable on medicare making it reasonably affordable. It should generally take around 6-8 session to get a good outcome with something like this.

There are a number of behavioural and thinking techniques that you can learn to help you reduce your fear and get to the point where you can cope with seeing a dog on the street and not panic and also to help you feel more comfortable going out without worrying about it constantly. You'll get relaxation techniques, information about the physical panic response, and help to change your thinking to be more helpful - like searching for evidence of a threat - and more realistic.

HTH. I really encourage you to seek some help from someone qualified in this area. It is really treatable.

btw - my fear is of confined spaces. I don't think I have a full blown claustrophobia but I do have to concentrate on my breathing and staying calm when in small spaces, especially crowds and lifts and things.