How much ache can one heart take

Hearts are quite the amazing organ.  It keeps working after it's broken. And what I can't believe is that it can keep breaking. Isn't there some point where the heart can't break any more? I know, random question. Let me back up. A family just lost their 2 month old baby boy. They are an amazing couple and wonderful  and my heart breaks for them. I attended the memorial today...at my church with my minister...1st funeral service at my church with my minister and for a child...that I've been to since Grace. It just ripped that scab right off my heart and all the pain came flooding back in. That hard time breathing, that ache in the chest and in the gut.  It just hurts so bad. And then hurts extra b/c it's hurting for the family b/c unfortunately I can imagine the pain they feel. People say to me all the time they can't imagine what it must be like, what it feels like, how I do it, etc...I don't want people to imagine or understand. It hurts too much and I don't wish that on anyone. So to know it happens again...it just hurst and makes it fresh all over again. And in the same week we've had 2 more SMA diagnosis in Texas - breaking for those families that are realizing their  worlds just got turned upside down like they never thought possible.  One of BF had a miscarriage, which breaks my heart and starts all the why questions again. And the it's not fair thoughts again. My brother had to put his cat down (I know not quite the same but we'll just pile it on there). All this week. All on that little heart muscle.  How does it keep going when it is so heavy and broken in so many pieces?  And then I feel ridiculous for feeling so hurt b/c none of those losses are even mine. How selfish of me to be so upset by all of them when it's not even me. It's them. They are going through it, not me. 

Nothing makes sense. Nothing. Chaos. If they are lessons to be learned I'm tired of learning. If what doesn't kill us only makes us stronger I'm strong enough. If God only gives us what we can handle I'd like him to trust me a little less. And at the same time I want to do more. I want to be more available. I want to help more people. But how do you do that when it breaks your heart every time too?  I just don't know...no answers...just pain and questions....