There is life after NATS. The are many many many ATCOs out there who have forged successful careers outside NATS, and many who have returned to NATS, who were chopped during their NATS cadetship. NATS have chopped many 100s of cadets - all of whom were originally selected for their apitude. The reasons for this have been debated on this forum many times and I don't intend to start that debate again. However, I will say this. Being chopped by NATS does not mean that you are not ATCO material.
In days gone by, many chopped cadets left with a student licence. Every cadet had to do the Aerodrome course including Law, Nav and Met. However, completion of ADI is no longer a requirement and so cadets often get chopped with nothing to show for their efforts.
There are definitely opportunities if you manage to complete the ADI course. There have been some very negative posts from some on this thread. Take no heed. The airport I work at has just recruited a young lad who self funded his ADI course at BAe Cwmbran.
There will always be those who pompously suggest that if you were chopped, you must have been crap. That just isn't true. PM me if you want more pointers. All the best.