Zak,
I hope what you are describing is "Letting Down" the bowstring.......NEVER just let the string go at any point in the draw unless you are shooting an arrow at a good backstop. Even a half draw "Dry Fire" can damage your bows parts.
If you can't get it all the way back, simply guide the string back to rest the entire way with your hand/release still hanging on to the string.

I'm going to give you some advice,and it's not meant to insult you in ANY way shape or form......
If you ordered the bow from a Pro-shop have the tech guys set you up properly for draw length/draw weight/arrows /accessories etc. Most shops that you buy a bow from will be happy to help you out getting started properly.
They should be able to set your bow up properly for you and your abilities.

If you ordered the bow from some other source, STILL head to your local pro-shop and see if they will help you.......It's a good idea to develop a relationship with a shop that you can trust. It sounds like you will need some professional guidance with your new purchase. You will most likely have to pay for services that might have been included with a pro-shop purchase, but start a relationship with your local shop.

And of course you can always bring your questions here......but if you are a beginner you will most likely benefit from some hands on help.

Good luck,
Matt