Thanks for posting your query.
Your blood pressure according to your age and type II diabetes
status should be around 135/85 mm Hg.
Considering the mentioned values of your blood pressure, it should be labeled as normal.
Normal diurnal variation is also present in each & every human being whether diseased or normal.
Do you have any other symptoms apart from weakness and tired?
Lack of energy, tiredness
may be due to hypoglycemia/ arrhythmias/ depression
You should consult with internal medicine specialist and should go for blood sugar and ECG check up.
If these investigations are normal, then you should consult with psychiatrist
and take proper treatment.
Dr. Mayank Bhargava