I couldn't possibly add anything to Genghis's excellent treatise except. perhaps, encouragement.
I wish you had mentioned a degree in an aviation related discipline because that seems to be the norm these days.
But if, at 22 yrs old, you have a yen to become am member of the Test Flying community then you are streets ahead already. Build on your flying now by taking a passionate interest in the didactic aspects of aviation. A lot of it is boring but none of it is useless.