I agree with the others. Most NF editors want a proposal, not a whole book. Work on getting an agent and putting together a proposal. I had about 5 chapters written for my book (mostly because I had flirted with self-publishing). I submitted two sample chapters with the proposal and the editor wanted to see a 3rd one before buying. But I had an insane deadline (3 months after signing) to get the full manuscript in so it was good that I had so much written.

The writing you've done won't go to waste but concentrate on agent and proposal. I'm an attorney yet I could not have negotiated the contract my agency's attorney did because book contracts are not what I do. Best to have an agent before signing anything.