Why not? It's your life. People can do most anything they want if they are willing to discipline themselves to do what is necessary to reach their goals or are willing to accept the consequences of their actions.
I suffer from several conditions that cause me to live in constant pain, it has been over a decade since the last time I didn't have any pain. It's my life, if I choose to end it, it is my choice. If I make the choice to end my life and relieve the pain, I have to accept the consequences of what that action would do to others. If I was willing to accept those consequences, then there should be nothing preventing me from making the choice I want to make. I chose not to make that particular choice for several reasons, one is that I do not want to be responsible for causing pain to those who might care about me, but it is my choice. Some may argue that because it would cause others pain that they should also have a say in the choice, but I don't really accept that argument. Sure my death would cause them pain, but they would also know that I no longer have to suffer constantly, and that may offset the pain of my departure. Right now I don't chose to quit, that doesn't mean that at some time in the future as I deteriate and suffer more I won't chose to, but I don't think I will, it just isn't in my make up to do it. But I don't hold making that choice against those who do chose it, it's their life and their choice.