What is my purpose in life?

I'm sitting here, and this is the fourth time I've tried writing something.  I have so much on my mind and I just don't know how to say it.  So, I guess I'll just write as I think and if it doesn't make sense, well...sorry about that!
First up, the Rapture. Supposedly happening this Saturday (May 21st), now I know that nobody knows the day or hour. I've got that. I promise.  But deep down? In that dark little spot that everyone has but nobody ever really wants to talk about?  In that deep dark little corner of my mind, I'm scared.  Why you may ask? Because I have children that I am terrified aren't saved. K1 is my smart-as-a-whip daughter, too smart for her own good at times. She doesn't believe in God. Period.  I know that she has passed the age of accountability and that terrifies me.  K3 is only eight.  EIGHT.  The thought of the rapture happening and her being left behind, alone...is enough to take my breath away.  Everyone I ask says that the age of accountability differs with each person, but it all boils down to being able to know the difference between right and wrong.  She knows right from wrong, so it scares me. She has professed to have asked Christ into her heart, but she's eight.  Do you know how many times I made that same profession before I finally got it right?  Shoot, there are still days when I question myself and I am 37-years-old.  I have friends and family members that I know for a fact aren't saved and that breaks my heart.  I don't want to think about anyone being left behind, but I know that it will happen. 

Next up...what is my purpose in life?   I'm just kinda drifting along, not really sure what it is that I'm supposed to be doing.  I see so many people in need and my heart breaks for them.  I wish I had the money to help people.  I know what they are going through, I've been there before.  I've been homeless, I've been hurt.  I know what it is like to feel like there is nothing left to live for and to feel like giving up. But I also know what it feels like to have God reach down, touch my life and turn me around. It is only by His Grace that I'm not out in a gutter somewhere drinking my life away or shooting up to make the pain go away.  I know that He has made changes in my life and I don't spend enough time thanking Him for all that He has done. God has been so good to me, He has blessed me with a roof over my head, food in my stomach, clothes on my back.  I just wish that everyone could see, understand what God can do for them. 
Wow, this is actually helping my stomach not hurt so much. Am I a perfect person? Uh...no.  When I see someone that I don't like having wonderful things happen to them..I have that twinge of 'are you kidding me? THEM?' yep, I sure do.  I still have to fight the urge to gossip about certain people and most of the time, I fail :(     
I am an emotional eater.  I want to lose weight so badly but I'll sabotage myself.  I hide behind my weight so that I can have something to blame my failures on.  Relationship didn't work? It was because I'm not skinny enough for so-and-so.  Hard time fitting in at church? It's because everyone else is so skinny and not wanting to get to know the fat woman.   My weight has been my shield for so long that attempting to shed it scares me.  Who am I if I'm not heavy?  Being heavy has been my identity for so many years that I'm afraid to discover who I really am.  I guess that is what this all boils down to on the inside..in that dark little spot.  Who am I and what is my purpose in life?