When is enough really enough?

Have you ever had multiple series of events that continue to just pile on you with the ones causing these events don't even seem to realize they are doing it?  Well, I've been on the receiving end of such events now for quite some time and I believe I have finally reached the point of it all just being enough. 
When you truly have nothing but the best intentions at heart and even when you have to do the hard things, but still for the right reasons and people just want to assume you are up to something or trying to deceive them, how does one continue to go through and feel these things without just giving up?  Trust me, I am ready to give up, but there are others that depend on me to do the right thing that keep me from giving up right now, but honestly, that may not be enough if things don't improve and improve soon.
There comes a time when a person just gets tired.  I don't mean, I need a nap or go to bed kind of tired, I mean physically, emotionally, and mentally tired that no amount of sleep or rest will correct that feeling.  The only thing that could correct that kind of feeling of tiredness is peace.  I may never get that peace until the Lord reunites me with my son in heaven and that saddens me terribly, but at some point I will have to face the reality that, that truly is the only time I will feel that.
Sadly even more, I'm starting to find myself feeling like that is fine the it will take that to have that kind of peace again and I never wanted to be that kind of person.
So, when is enough really enough?  How much does your heart have to break before you just give up?  For me, it feels very close.  There is a piece of my heart that is there now and I hate that as I have never been that kind of person.  I don't want to be that kind of person, but I can honestly say right now today, I am defeated enough and feel so broken that a piece of me is becoming that person I never wanted to be.  I feel I am getting more and more hard in my heart and for me that is one of the saddest things. 
I work so hard every day just to put my feet on the floor and face every day with the best attitude I possibly can, because it would be very easy for me to not do that and live in my bed and cry for my baby, but I do not do that.  So to fight that kind of fight 24/7  365 and then have all this other STUFF piled on top of that makes it even hard to want to continue doing this.  I am so close to enough being enough for me.