I'm am RN of 30 years with Type 2. Yes Diabetes in general can be a contributing factor to fatigue. But I find that I'm most tired or sleepy when my blood sugars are elevated. The best thing to do is try to press through it, get up and move, but if all else fails a short 20 minute power nap and a big glass of water usually gets me feeling better. Caffeine can help in the short term but it dehydrating so in the end you feel a little foggy when it wears off. Try to drink a glass of water for each cup of caffeine containing beverage to Ward that off. But yes...I to get fatigued easily.
Swinging blood sugars typically make you feel terrible. And it's bad for you as well.
Best way to avoid this is to eat very low carb, exercise, manage weight, and take medications as necessary.
Please also get your thyroid checked. Thyroid conditions often go hand in hand with diabetes (co-morbidities) and can also make you feel terrible.
diabetes does nothing... its high BG or rapidly changing BG or low BG that do things. Control the BG and control the "does diabetes cause...).