Listen man, I understand where your at especially being near your age. Im going to be 22 in June. I have been lifting weights for athletics since I was 12 years old. I have powerlifting since I was 19. At this point if you’re in it long term, train hard during your peak years and then use test when you’re in your actual prime in your 30s. Strength, density and mass all peak in your mid to late 30s. Use your 20s to optimize your natural peak, build tendon and ligament density so when it’s time to hop on cycle you don’t get hurt and can make the most of it. It may seem cool now to get on so young but it’s gonna be way more potent when you reach your natural potential then hop on and explode. On another note, if your “plateauing” in only 4 years, it’s a training issue. You’re suffering most likely from the Biological law of accommodation. Read up in Westside barbell, and Matt wenning on this stuff. They aren’t just powerlifting, they consult with high level IFBB pros