Should I give up on piano lessons ?

My son is learning his grade one pieces and has been for nearly  a year. He takes an hour to have a lesson as he goes back and forward from the piano. Thankfully his teacher works at a special school and is v parent with him . When he gets anything wrong he gets v cross. He doesn't take on challenges well and sees a new piece and automatically says it is too hard 

It is so hard to get him to practise as he gets so easily frustrated and what should take ten minutes can take up to 40 .

I teach piano and want him to have the same skill. Am I being selfish ? I already gave up my dreams of having a West end star for a son !!! 

When I ask him if he wants to stop he says no and gets v upset. He loves his teacher but the whole thing just causes so much grief.