"You ask what will happen to you if you commit suicide?"
No idea.
I can say this.
You may miss out on the best thing that you don't see coming.
You say it is a goal.
I ask, why have you made it a goal?
At least reevaluate your goal.Take a good hard look at it.
Instead of a goal of suicide most people use hope.
Hope can be a powerful tool.
Make a list of all the things you would like to do or become.Then find out what is stopping you from doing or becoming them. This could be a new goal.
Just because you had a goal since you were 12 does not mean you have to keep that goal.
You can change that goal at anytime.Make new goals,or at least reexamine your goals.

Don't use a permanent solution on what may be a temporary problem.