Your glucose levels have gone up on stopping the tablets, so perhaps you have type 2 diabetes, not LADA. Some folk with type 2 have their pancreatic beta cells switch off insulin production when glucose levels go high, needing insulin treatment at that time, and causing confusion.
If the tablets were upsetting you, then it is sensible to review and consider stopping them as you have done. Metformin and linagliptin probably help the insulin treatment, and other tablets such as empagliflozin, pioglitazone and sulphonylureas have pros and cons.
So, as you say, it is worth discussing this with your diabetes consultant - do you just push the dose or switch to a different regime of insulin? You do not mention your weight / BMI.
best wishes