Go back to your GP and ask to be referred back to the counsellor, eight weeks is not long enough in severe prolonged depression. I had counselling on the Nhs for over a year with top up sessions if I need them. You would also benefit from increasing your activity levels, worth asking if they have a system of referring to a gym or other fitness activity. Again I am on a 12 week free gym referral for weight management but it really helps helps my mental state too.
We can only support from a distance sit in your doctor's surgery and cry, show him what you posted here, please get some proper help