Does the pain ever end?

Ever since I can remember I have had some illness or another each one worse than the other. As a child I had breathing troubles which went away only to be accompanied by epilepsy which to went away and replaced by diabetes. However diabetes never went away and now I have bipolar. My life seems it is not worth living anymore. All I have ever wanted was to be "normal" and that shall never be. I have 3 great children that give me a small hope of living but that too makes me wonder if i am any good for them. I cannot live my own life, always someone living it for me but then I wonder, should I live my own life? The choices I make always seem to be bad for me landing me in jail or worse ( in a marriage I really dont want). Well the marriage part was mor my parents wanting than my own. I hate my life, hate who I have become. I feel like a public toliet for others pleasures and desires.