I'm sure you can given that you have only just started insulin therefore you won't have the records. Maybe give them a ring to put your mind at rest tel: 03007906801
As for retraining they do offer courses they vary from region to region I don't know why also the RNLI are offering courses which...
They won't take your licence read the new DVLA rules you have to show that you are monitoring and checking sugar levels on a daily basis for a 3 month period and you have a medical each year.