After reading your description, your body is not very flexible. Do you belong to a naturally hard person? But you are young. Of course you can improve yourself through practice. Don't be too hasty. Practicing in a painful situation will backfire.

Warm-up is the premise of improving soft opening. Ligaments soften when you have a fever, leg press. When your legs are exhausted, it doesn't hurt so much.

To master the correct leg press method, cooperate with breathing, inhale and get up, exhale and press down, and feel the pain of leg ligaments. Don't push hard, it's no use. You can slowly lift the handle of the leg press from low to high.

After the exercise, you should learn to relax muscles and ligaments, shake your legs and hands, obviously feel your body hanging there, and all joints and muscles should be relaxed. At present, your ligaments and muscles are painful, so you can appropriately reduce the practice time, relax and soak your feet with hot water.

Have confidence in yourself and persist in not giving up. It will be effective. Wish you success!

Supplement: Training is to increase the amount of exercise. Whether the fatigue of ligaments or muscles is relatively increased, not only the body needs to relax, but also the mood should not be too eager for success. As long as the correct training methods are mastered, the flexibility of ligaments will be improved.