Hi twedspeed,
Hypos can make you feel really bad. For me I've not had the really bad headaches but I do get tired. I'm type 1 diagnosed 3 years ago. I'm a 62 year male with a 20 year old daughter who was diagnosed with type 1 when she was 9 years old, so I've lived with diabetes for quite a few years.
What type are you and are you on insulin...not novorapid and levemir or lantus(glargine). Some folk just cannot take analogue insulins and get tiredness/fatigue, foggy head, sleepy, muscle and joint pains and can have problems with BG control. Look up Lantus on the diabetic forums to see some of the HELL that analogue insulins can cause. Have your vit D, Vit B12, blood pressure tested. These are tests that, for some reasons, don't get tested as part of the normal diabetic tests. I'm now on animal porcine insulin and feeling much better than when I used novorapid and levemir and later lantus(glargine). Get all the usual tiredness test like thyroids iron just in case there are other problems. After going through 3 years of HELL, I would recommend that you first look at what sort of insulins you're on.