:( I have been there many times. I have learned not to focus on numbers, but measure success by how I'm doing. It sounds like you are not happy in general - I wasn't either, until we made a big move last April and now live closer to parents and friends again. But, I changed a lot of things about me as well. Not easy, but I did it.
Probably the biggest for me was to learn not to rely on sugar for energy. I had to cut it out completely for a while and only had dark chocolate as a treat, which is also a great antioxidant. Especially for you as a diabetic, this would be a great thing. There's a team for that on SP, but I am not that good at staying involved in those things. For me personally it's important to have a good life outside the computer and to try my best to get my butt of the couch and get out - friends are so important.
Do some things just for you that will make you happy. Imagine doing something that you like, then get up and do it! Even if it'll be hard - the more difficult, the greater the achievement (as long as you set reasonable expectations).
Also, if you are really depressed, please see a doctor or therapist for help. There are also free services to help with mental issues. Depression sucks, I've been there....
You can do this! Put yourself first!!!