@Watty62
Maybe you should ask your doctor to help, by doing some more investigations, it's always easy to blame things under the diabetes and mental health banner, especially if a patient has those problems, ask your GP to take them out of the equation and see what questions he would be left with and if he can come up with another route to investigate.
I used to feel shattered every day, and also down in the dumps mentally, after years of this being put down to my diabetes and other physical conditions such as lupus, ankylosing spondylitis, arthritis in both hips and spine, my GP advised anti depressants I took them for a few weeks, they did absolutely nothing other that give me vivid nightmares.
Years later, it's now been rectified, when I was diagnosed with low testosterone, mentally I'm happy and energetic my partner says I've reverted back to the old me that she first met some 16yrs ago, I'm also buzzing with energy typically I now go to bed around 10:30pm and I'm awake at 3am and ready to leave the house by 3:30am, after one week of treatment, I walked over 80miles more than 3 marathons as part of my exercise routine prior to treatment I'd struggle with just one mile, where I now only need 4-5hrs sleep before I could sleep 18hrs a day.
Watty, All the best with getting things sorted.