I'm 22, can my jaw and chin still grow naturally till 25? Or that is impossible? (Photo)

Joining the gym won't work to enlarge the jaw and at 22 you will have reached the stage of full growth. Sometimes, dental work can improve the shape of the jaw, for example, if you have an underbite. Secondly, fillers are a non-surgical solution to augment the size of the jaw whilst also stimulating collagen production. If you did want to look at surgical options, a chin implant or a sliding genioplasty would be appropriate. 

For most patients, the mandible quits growing it by age 18. The photograph demonstrates a weak and recessive chin profile for which a chin implant can improve. Chin implants are manufactured in a large variety of sizes and shapes which is best determined to be placed at the time of the consultation and examination. In our practice, we place the chin implants under local anesthesia through a small incision underneath the chin which takes approximately 30 minutes. In our practice we  use Implantech solid silicone chin implants which can also be custom carved when necessary to match patient's unique anatomy. For more information, diagrams and many examples, please see the link and the video below

You are past the point of any further jaw or chin growth. There are no injectable stimulants to make it growth out further. Only surgical jaw and chin surgery exists for a more pronounced lower facial look.

Your jaw will not grow more at the age of 22. You have reached skeletal maturity, which is the time we operate on jaws for advancements, augmentations, etc. Only surgery will change the shape.

I doubt your chin will grow any more after age 22.  I believe you would benefit from either a chin implant or advancement genioplasty to improve your chin weakness and profile.  Find a board certified surgeon who does frequent chin surgery for the best outcome.  Good luck.  Donald R. Nunn MD  Atlanta Plastic Surgeon