There are 2 issues with this question.
As I am sure you know, to become an aeronautical engineer by definition, you require a degree. To become a pilot you don't. As a pilot, a degree is a nice thing to have but not essential. I did Aero at degree level, however, it really was a contingency plan, just in case I did not make it as a pilot.
You have to ask the question, what is your heart is set on, engineer or pilot? One thing you have on your side is time, you are only young and have you whole future ahead of you, so plenty of time, even if you did decide to go to Uni, you would pop out the other end with a good qualification and the option to go onto pilot training if you so desire.
Another thing is it all depends on personal circumstances, with regard to commitments, family, financial etc.
Obviously, in this present climate getting a job as a pilot will prove very difficult, I am not about about the Aero Eng industry and the demand for engineers? With the current economic situtation, if I was in your shoes, I would consider getting a degree under my belt, have it on the back burner.
It is difficult to advise you as there are so many variables.
All the best.