1. Separate yourself from your work.
Your identity is found in Christ, NOT your writing. Before sending your work out, take a step back from it. Realize that this isn't personal anymore, it is a product that you made. (I learned this from Thomas Locke at Realm Makers last year.)
2. Realize that beta readers are your friends.
They offered to critique your story because they want to help YOU. It isn't an evaluation of how good of a writer you are.
3. Be open to change.
I've beta read for some people who defend every single editing decision they made. Yeah, that's a little frustrating because how are they supposed to get better?
4. It's okay to be upset, but don't dwell on it.
This isn't quite as easy as it sounds.
5. There's always another novel.
So this novel is beyond hope (at least for the present time). Write another one! And another one! And another one until your writing improves. Even published authors haven't hit their "ceilings".