I just wonder why you have wasted so much time if you wanted to be an ATCO when you were quite young. I was in a similar boat but pursued it from the time I left school with just 2 GCE O levels. I wrote to every airfield in the UK and eventually managed to get a poorly paid, grossly overworked job at a small airfield as a "trainee controller". This led me to apply to International Aeradio (now SERCO I believe) and I secured a place on an ATCO training course and was eventually posted overseas. After 3 years I returned to the UK, having come home on leave and taken my UK Licence exams. I got a job at a non-state airfield, working TWR and APC and applied for a Civil Service ATCO position as soon as an ad appeared in Flight. I was accepted with the lower educational qualifications based on the fact that I had recent ATC experience at home and abroad. I was posted to Heathrow - Hey Presto! childhood ambition achieved.
This is just to say that without the basic education requirements, life can be difficult, but given a lot of work and a bit of luck what you want may just be achieved.