I am a 20 year old and my ears are sticking out. What if I try cartilage but not otoplasty? (Photo)

Good morning, thank you very much for your question, according to what can be seen in the photograph, the recommended procedure is an otoblastia to close the upper wing of the ears, the procedure consists of:Ear SurgeryOtoplasty is a surgical procedure aimed at correcting prominent or "protruding" ears.
The aim is to achieve a repositioning of the ears, closer to the head, and not absolute symmetry.
Otoplasty is usually performed in children from 4 to 14 years old who are dissatisfied with their ears, since in many cases it poses a problem at the level of social relationship, although it can also be performed in adults.BeforeIn the consultation, the plastic surgeon will evaluate the problem to be corrected. Your general health will also be assessed and you will be given specific instructions on how to prepare for the procedure.
DuringOtoplasty is performed in the operating room under general anesthesia, its duration is given between 1 and 2 hours.
AfterAfter Otoplasty the ears may hurt for a few days. Returning to school or work is usually possible in 1 week, but you should limit physical activities for the first month.RisksComplications after an Otoplasty are infrequent and among them we can find: hematoma, infection or healing problems.ResultsAfter an Otoplasty, the result is not immediate, as in most procedures, but you have to wait for the edema to disappear. After that time, the results are usually permanent

Otoplasty is a procedure that targets the cartilage to pin back the ears to a more aesthetically pleasing position. This treatment is minimally-invasive and can be performed using local anesthesia. Recovery is typically about one week and the results are permanent. I encourage you to schedule a consultation with an experienced, board-certified facial plastic surgeon to learn more about this procedure and determine whether it is the right choice for you. 

the ears can be pinned back with a simple surgery that will only remove the cartilage. that's commonly done. I think the important issue to keep in mind is that ears are a high risk for Keloids scars esp after surgical procedures or trauma. Keloids can completely distort the shape of the ears. people with higher risk for keloids need to be aware of this adverse outcome 

There is no problem in the anatomy of your ears. the reason behind the protruding is that the concha of the ear is a bit bigger than it should. the problem can be solved by reducing the concha surgically 

This is from inadequate “folding” of the antihelical fold. The gentlest method of an otoplasty is the   Dr. Merck stitch method.

Your ears have the correct anatomy, but protruding.   This is from inadequate “folding” of the ante helical aspect of your ears 
A procedure called “incision-less” Otoplasty is appropriate.   This re-sculptures you ears without incisions.