Hello, Isabel. No, I don't think Type 2 can turn into Type 1. I suspect one of two things,
1) You were misdiagnosed and always were a slow onset type 1. There are antibody tests that can distinguish the two, but they are unreliable, especially when time has elapsed since diagnosis. There is also a test called the C Peptide, which measures how much insulin your body is producing, which can give a good indication.
or
2) You are type 2 but require insulin to support your pancreas, but unfortunately some health care practitioners get the wrong end of the stick, and assume that if you are on insulin, you must be type 1!
Whichever type you are, the most important thing is that you are getting treatment that works for you, as an individual.