Good to hear from you. I was'nt sure if you were trying to write me a poem in that first bit, ..after having had a glass of wine or 2!!!
I think you need to try to keep calm about all of this. Whatever happens on the 25th April in South Africa, the next day your life goes on! Try to enjoy this challenge and just do your best at each training session you do every day.
The more swimming you do, the stronger you will become. Are you swimming with a triathlon squad? ..it might be helpful to swim with other triathletes.
I hav'nt really heard of loosing concentration on the bike before? Are you tired when you start out?
Maybe you need to set yourself some bike sessions that are exciting, like new routes, ride up a steep hill, or try a time trial. Then it is difficult not to loose your concentration!
Remember that all the training you do from now to the race will help you, so make sure you concentrate!! then it will pay off and you will have a memorable day on the 25th April.
All the best,