Are you on any medication - this could make you light headed? Your sugars could well be down - when mine are below 4.4 I feel light headed and slightly trembly. I was told when I was given gliclizade that it could produce a dramatic drop in my sugar level which could make me light headed. Get your levels checked I'd say - you may need to invest in a monitor for your own peace of mind - I did that and I feel like I am more in control rather than waiting for doctors to deign to test my bloods (which my GP has yet to do!).
My levels were 15.9 when I started and I now have a fasting level of between 4.2 and 5.9. This is 6 weeks on from diagnosis.
Much improved on what I was (and over a stone lighter in weight!)
Fingers crossed you get more help from your nurse.