If you haven't sent in what you have written above then I would suggest you do not.
There is no prospect of being able to drive away from court. For 59 mph in a 30 zone you are facing either 6 points or a ban of between 7-56 days.
If you receive 6 points then you will be revoked under the new driver's scheme if you are within the first 2 years of driving. The advantage of that is that you would be able to drive again as soon as you pass your test again.
If you want to pitch for that you need to be emphasising the shortness of any distance driven at speed, the absence of heavy traffic, the clemency of conditions and visibility if indeed these things are true.
If you are happy with an immediate ban then you need to be emphasising the same points but also your hitherto good character and early guilty plea.
There is no exceptional hardship argument because you are not a totter although you can make the point that a ban would impact you harshly because of your circumstances.
The advantage of ban is that it would be fairly short.
Can I clarify anything for you?