If you enjoy your work, diabetes is not a reason to change it.
You may need to make a few adjustments (which under the UK Disability Discrimination Act you are entitled to require) such as frequent monitoring of your BG and reducing your insulin to avoid hypos but diabetes should not be a reason to stop doing what you want.
Just look at sportsmen with diabetes you do very "manual work": I look at people like Henry Slade who plays Rugby for England as inspiration of what we can do.
As you say, you are newly diagnosed so it will take some time to work out what you need to do but I do not think you should change your job because you have diabetes.