I apologise for posting again. i do not want to hog the thread. However, please speak to the school and the SEN department of your Local Authority. After seven years of struggling, the school/LA should be doing something.
My son refused school due to mental health difficulties and he made the most progress when the local PRU began to send a regular tutor. The tutor built up a relationship with my son and he began to attend the PRU.
I just wish my son had attended the PRU sooner. He was given 1:1 tuition, but most importantly, someone began to work with him to find strategies through which he could manage his emotions a little better and he began to make one or two positive relationships with other young people.
He took 2 GCSEs and the grades matter less than the fact that he actually sat the formal examinations.
Our next battle is college. His anxiety levels are high, but at least we have the positive experience of the PRU to refer to.
Finally, does your son have a passion? If he is fascinated by cars or fitness, there are vocational courses that he may aspire to or, as another poster suggested, he may be able to access these through the 14-16 curriculum at college.
Good luck anyway.