We bought a testing kit

Last night we bought a Touch one Ultra glucose monitor and late last night my husband did a random check and it was 548. He took it this morning after fasting and it was 368. Bad bad bad. Diabetes insipidus only has symptoms of thirst and peeing alot which is my husbands only symptoms but Diabetes Mellitus 1 and 2 are the only ones that it could be right? Since he does have high blood Sugar obviously. He has the symptoms of diabetes insipidus but I don't think that type of diabetes has anything to do with high level of blood Sugar does it? Anyone know for sure? He is going to the doctor tommorrow. Also I am new to this altogether and I am worried about what to cook and how to etc.... Since his blood Sugar seems to be skyrocketing has anyone tried anything that they think might help him in terms of natural supplements? Thanks!