As a parent you may be overly ambitious for your son, but you should be more realistic. You must take his interests and abilities into account. From your mail it appears that he is interested in graphic designing and in modelling.
Perhaps a course in Graphic designing course would be acceptable to him, and it would provide employment after modelling is no longer possible. Instead of forcing him, try to encourage independent thinking and decision making.
If he takes a decision himself, he is more likely to work towards a goal.