Hi Emily.
Welcome to the forum. Have a good look around especially the Type 1 forum area. Can you tell us what your 'very strict diet' actually consists of ?
As for the problem you have with hypo's if it has the Dr's, Nurses and Consultant's confused. Then I think I am in good company...... :? My normal response would be too much Insulin, not enough food, unusual amount of exercise, delayed meal, stress etc. In your case that doesn't seem to apply and there may be something else going on.
Hopefully there will be a Type 1 along soon who may have experienced the same and can advise you better.