Sounds to me like depression or the precursor to depression. I am particularly concerned with your last statement in which you refer to your last full time job

Sounds to me like depression or the precursor to depression. I am particularly concerned with your last statement in which you refer to your last full time job... having a stable job or lack of one can really affect your mental health. A job is not just about the money, it provides you with a sense of self worth and the good feelings that you are providing a value to society. Maybe consider finding a job in a different field, even something mind numbing like manual labour that will force you into a routine again, then you can still do your contract work in your spare time without the pressure and stresses you are currently putting on yourself. If that won't work for your situation I would say try treating your current contract work as if it were a full time job, set limits for yourself, go to sleep, eat and exercise aND work at the same times every day. Set yourself both professional and personal goals, write them down and review your progress in achieving them on a regular basis. If that still doesn't work for you, consider consulting a professional for a pharmaceutical solution. Finally clean up your environment and be mindful of how much of an effect a messy unkempt lifestyle can have on every aspect of your mindset. Cleanliness is godliness. Good luck depression is a tough hole to climb out of but it is possible.