I'm having my fourth session tomorrow. My confidence is still through the roof and has been almost constantly for the last 5 weeks. I have crap days where I don't feel confident, but this is normal for anyone, and it does not feel like I am in any danger of reverting to my old, unconfident self.
Dedicated sessions which deal with one problem, or a small number of related problems that can be conveniently lumped together and treated at the same time, are very effective.
Hypnosis is more effective when repeated a lot. People need to read, see, hear or do something an average of 16 times before they "learn" it. The best and cheapest course of action in the long term is to buy or download a good self-help mp3 and listen to it every night for at least a month.
I would recommend listening to the same one for at least 1-2 weeks before using another one. You don't want to confuse yourself with mixed messages or by trying to do too much. Take your time and do it right. Prioritise the problems that need treating most urgently and deal with them first before you even consider doing anything else.