Hi Linda,
If you are on insulin then your license needs to be renewed every 3 years and they usually want a conversation with you and your doctor. You should not admit to any hypos as I have heard of people having their license revoked for 6 months. This means that it becomes difficult to have a frank and honest conversation with your doctor, because they have to record hypos.
I have never had a hypo (or anything close) whilst driving but I have had one cycling, once. I did not share this with my doctor.
I also drive a small van for work occasionally and would be stuffed without my license. You cannot drive a lorry (the sort you rent to move house with) if you are on insulin without special permission, I believe. They took this category off my license straight away.
So, you see, if you can avoid insulin then it's worth doing. I have tried once to come off it, and failed. I am lining myself up with a series of hospital appointments to better understand my condition and then will try again - but ultimately it may be impossible. Hope that helps.