Happily Frustrated

I want to pick up my book again, I'm just not sure where to start. It's done... It's been edited 4 times... It's been rejected 27 times (Still waiting on 3 more) although one was a full request. Something is missing and I can't quite figure out what.

Here are my potential issues...

Too much back story. - I can't figure out how to NOT use the back story. I feel like it is so relevant to understand the rest of the book. And to take it out...can we say WEEKS of work. (not that I am opposed to this...just scared of it)

Heaven and Hell vs. The Eternal Paradise and The Everlasting Night of Fire - I have to admit, changing it up to just say Heaven and Hell sure does bring a whole different feel to it. It's a more "Final" feel to the consequences. Possibly a good thing...however it takes away from the world I was attempting to create. Not to mention all the questions that come into play about my beliefs and God and such which in reality have NOTHING to do with the story.

Discrepancies - My brother and other people have pointed out some big issues with my story. One being, "Why does she find Michael more beautiful than all the celestial beings that are OBVIOUSLY more beautiful than him." Good question...I thought I "showed" that, but it appears I haven't.

Confidence - Yeah...unfortunately the confidence has slightly slipped. I have this awesome story that just isn't coming off right and the beginning just isn't able to pull anyone in, then I have this awesome beginning to another story that grabs you right away, but I can't figure out where to go with it. (Both about COMPLETELY different things...) And with the lack of confidence comes a lack of creativity.

Now I say I'm happily frustrated because I don't want anyone to think I am complaining. Complaining would not accurately portray my frustration. I'm patiently embracing this frustration as I am in love with being a writer, I'm just wishing I had the answer to my problems.
And I'd possibly like to have a healthy dose of confidence shoved my way so my creative juices will get back to flowin!