I agree with Squawk7500. When I tried to get into ATC back in the 60s I only had two O levels but I passed a Civil Service examination for a post which, for outsiders, required 5 O levels. I used this to apply to become an ATC Assistant but was refused as they were adamant about the basic requirements. I don't know if this has changed. Your age is not on your side, although expect a flood of posts from people much older who succeeded! The training is fairly tough and goes on until one validates at an ATC unit, which can take some years especially at busy places. You may not get a choice of posting if you get through the basics. Lastly, if you are currently employed in aviation operations this could help..
I wish you all the luck in the world.