Hi Sarah!
Please don't be scared. I was initially diagnosed with Type 2, but I actually had a condition called LADA which is a slow onset form of Type 1. They diagnose this by carrying out two tests - a c-peptide test which measures how much insulin you are producing and a GAD antibody test that shows whether you have antibodies that are destroying your beta cells. From what you have said, I suspect you have had a GAD test and that it has come back positive - ask your doctor if this is the case. If so, you have LADA and progression to insulin is inevitable. It could take a few weeks, a few months or a few years. However, insulin isn't too bad and it LADA responds very well to it and gets your blood glucose into safe levels. If your blood glucose is constantly high, it puts you at great risk of serious complications, so this might be why your doctor wants you to go straight onto insulin to bring those levels down.
Take care and try not to panic!
Smidge