My face is very thin and small. I am very depressed. Please give me a solution to lengthen my face. (photo)

Without an exam your question cannot be answered.  You will need to see an Oral/Maxillofacial surgeon to see if othognathic surgery, genioplasty or using an implant is best for your specific case. It should be noted that patients with severely weak jaws or abnormally functioning jaws may be better treated with other facial surgery (orthognathic surgery), although a chin augmentation may be an option at a later time. These patients should seek the advice of a plastic surgeon to determine which course is right for them. Here is some information to help you make this decision: Candidates for Chin Augmentation - Patients whose chin profiles are weak but have normally functioning jaws are candidates for Chin Augmentation. Many of these candidates have used injectable fillers in the past to strengthen the protrusion of their chins, but are looking for a permanent solution. If you are one of these patients, then you are a likely candidate for chin augmentation

 Hi, I have performed many facial shaping procedures using dermal fillers, facial implants (cheek, chin), liposuction and/or facelifts for over 30 years. Following the beauty principles outlined in my book on face and body beauty, men look chiseled and handsome with angularity in the cheeks, chin and mandibular angles.  From the photos, your cheeks are flat anteriorly (in the front), the chin is weak as are the mandibular angles and there is excess facial fat in front and below the cheeks.  This combines to create an elongated oval shaped face.  The following procedures would create a more ruggedly handsome face.

Cheek augmentation with cheek implants to add angularity to the cheeks and mid face.  This would be combined with liposuction to reduce the excess facial fat to further define the cheek shape.
Chin augmentation, using a chin implant, to add projection to the chin creating harmony and balance to the lower face.  I have performed many Chin Augmentations using chin implants for over 30 years.  From the photos, your chin is weak.  A weak chin creates an imbalance making the nose appear larger, the mid face top heavy and the lower face look short that de-emphasizes the lips and allows early formation of a double chin.  Chin augmentation using a chin implant will add projection to the chin creating harmony and balance to the lower face.   I have found that placement of a silastic chin implant, through a small curved incision under the chin (also allows excess skin removal) to be very safe, quick, highly effective and far less invasive than a sliding genioplasty.  I perform chin implant surgery in 30 minutes or less, often using a local anesthetic alone.  In my opinion, you are a good candidate for chin implant surgery.
Augmentation of the mandibular angles using a dermal filler (jaw implants have too many unwanted side effects IMHO) to add volume, angularity and flare to the jaw line.
Hope this helps.