deppression is very common in diabetics, also your sugar levels are directly related to moods, speaking from experience, (I've been getting treatment for deppression for about 10 years now), I personally have felt similar to how you say you feel, and it is the hardest thing to actuallydraw a line under the past and try to start from scratch again, I had become lazy in my control and I suffered because of it, but a scare about 4 years ago gave me a wake up call I needed, and although my control is far from perfect, the process of starting afresh did the trick for me.
I started by active checking bloods every 2 hrs for 1st month during waking hours, whilst filling in a notebook as a food diary with bloods included, I was able to see what was causing highs and why I was going low, and through tweaking diet and insulin I was able to slowly get to grips with it, the swings started to get smaller, and as the underlying sugar levels came down my mood started to lift, which then helped me become more active and positive, which then created a snowball effect, as the mood lifted, the control became slightly easier to manage. BUT, AND THIS IS CRITICALLY IMPORTANT, YOU and you alone are the only one who can do it, others can help and advise, but only if YOU want to make a go of it. Put the time in for first month, but you have to be honest with yourself, if you have a choccy bar make sure you write it in your diary, and then when you look @ it at the end of the week, you will see how it affected your sugars, so if when you have another, you'll have an idea how to correct with insulin.
As far as the insulin doses went, for me, I for the 1st week took my normal doses at normal times and ate as I would normally eat, only difference was I was logging all food/sweets/****/coffee, the works, and be honest, look back afer the week ans see what bloods were in relation to food. This is the baseline, when taking correction doses of novorapid I used to over correct causing lows, which I'd again over correct , so I basically bounced from highs to hypos back to highs...... After I started this as a rule of thumb I used 1 unit of novorapid to bring down 1 full point of blood, but say my sugar was 25 and I wanted it to be ideally 7, I'd take18 units of novo, but I'd take an extra blood test in the 3 hrs following, in case the sugars dropped too rapidly, but when deciding on your correction ratio, that will be upto you to find out as everyone is different, but when correcting, never correct to a very low sugar level 4-5 is cutting it a bit too fine.
Also, if your sugars have been running high for a long period of time, you might find that your bodies hypo signs start earlier.
So week 2 is trial and error.
Week 3 is the tweaking stage, using minor adjustments to either carbs in OR insulin never both, as if you get it wrong, 1 compounds the other.
Hopefully by week 4 you should have a rough idea, of what insulin your taking for your carbs... for me it was quite easy doing the food diary as I'm a creature of habit, I eat basically the same stuff each day.
feel free to im me I'm no expert, but I've had to get a handle on it and can relate to the struggles with both the low moods and poor control.
And what works for me might not work for you, but give it a go....... :?