Can You Guess What I Am?

I’m what everyone hates,
I can’t be reasoned,
I have many dates,
Also many seasons,
I can be fixed,
Or at times I really can’t be,
Races are all mixed,
With me, no one can truly be free,
Everyone handles me in different ways,
Yet really I all affect them the same,
I can know many days,
It is really up to the person when I die,
I harden after a lengthy period of time,
I know many lies,
Yet if another intervenes I can stop on a dime,
I have caused many deaths,
I can make happiness dim,
I try to be lessened, sometimes, with meth,
Heartbreak is what I am.