I never throw any writing out - not ever.
If I don't like a piece, I cut it out but keep it in a file.
Later - sometimes years later - I may find it and whad'yaknow! It fits right in on a piece I'm writing now.
Keep going, don't give up. The only difference between a chapter and a book is just a few more chapters.
Thank you very much. :D I'll remember that and will stop throwing them out. :D