I am a 31 yr old Australian who started bowling leggies when I was about 13, I am currently living and playing up in Scotland. As per your other response, you should practice and practice possibly more than anyone else at your club! in the nets, often by yourself or with a mate batting or keeping as you have to gain some confidence in your action and landing your deliveries. You just have to keep at it, and persevere...it takes a long time to be consistent! Dont be worried about getting hit as over time you will get better and better...Hopefully you are not playing against senior guys all the time as this may make it difficult to get your confidence going.
When you are just trying to get the hang of it, it is important to understand the basics of how to bowl your leggie. You have probably already seen this clip but this may help -
YouTube - Shane Warne
Without trying to make things complicated, the basics of you action are important, in simple terms it is important to be relatively side on in your delivery, bowl over you front leg and make sure you
follow through fully down the wicket so you have momentum throughout your bowling action. Trying to spin it hard all the time!
May be a good idea just to come off a few steps or one when working on getting the basics right then building on that as you go. The more you understand the mechanics of your action the more dip in the air, drift, side spin, topspin and control you will have when bowling.
The above may be too much info all at once, but once you are happy that your action is repetitive and your are more confident in controling your legbreak then build from there with you topspinner, googly and so on. Bowling leggies can be so rewarding and sometimes embarrassing! stick at it and be patient.
Good luck!