I have everything I worked for and in the end what have I become?
What do you mean by everything? You literally have everything you ever wanted?
I mean the job, the salary, the car, the boyfriend, the friends. I have what I spent all my life for. And now I feel as if I haven't achieved anything.
It sounds to me like you've done a great job and accomplished a ton!  There's no reason for you to feel down on yourself after doing so well.  Cheer up!
I know I shouldn't be worried but I really don't feel excited about the fact that I've achieved everything I wanted.  I feel empty.
Being at the top can be lonely. You can only relish in your accomplishments and push yourself further to greater achievements. You should also consider sharing what you have with those less fortunate, so others can have a chance at success.