Hi
@merdockmoe and welcome to the forum. Yes the UK National Health Service does categorise blood sugar levels.
Using US mg/dl figures, in the UK 125 mg/dl and below is non-diabetic, 126-138 mg/dl would be pre-diabetic, and 139 mg/dl and above is diabetic.
Once we get in the diabetic range we are always considered T2 diabetic, even if our blood sugar level is controlled by diet, or medication.
Your fbg of 481 mg/dl is very high. Have you tried controlling blood sugar levels with a Low Carbohydrate High Fat (LCHF) approach to eating? A lot of us on here have found it is effective in lowering bs levels.
Have a read round the threads to see how it works and ask any questions you want to. The peopleon here are friendly and supportive, and you will get a lot of good advice.