One thing I'm surprised no-one's mentioned so far (and sorry if there's a reason for this), but Darren, you really need to start eating more.
You are being prescribed supplements for malnutrition, which suggests to me you need to urgently increase the amount and variety of what you eat. From the notes you kindly posted, I'd wager you probably need to eat another 1000 calories a day just to maintain your weight. I really think you do need to start looking at how you can add more food into your current diet.
While your BMI is 'normal', you're clearly not happy with it and as someone has pointed out, you can easily afford to gain another 10Kg and still be in a normal range.
You also might also be able to make some very easy gains without changing much in your currently lifestyle. If you develop an effective routine for waking up in the morning, you should definitely stop losing and start putting on weight.
Insulin allows you to store fat and stop metabolising your body fat and muscle tissues. If you forget to take your insulin in the morning, it won't matter how much you eat. Your body won't be able to use it, so it'll start eating itself. If you can break the cycle of missing your morning Levemir, you will get your BGs under control, which will do wonders for your state of mind, and you'll also stand a much better chance of getting your weight to where you want it.
Hang in there buddy. I know it's tough. Take baby steps in the first instance, you'll be surprised how far they can take you.