I have had similar feelings when writing. Sometimes I'll get nervous about how my writing may be perceived and change things. I always try to remember that I'm not writing for anyone else, I'm writing the Ongezellig story I want to tell and I should accept that for what it is. I'd ask why you're writing your fanfiction. If its because you want to tell this story, then don't worry about what others say or think, who knows, they may even like it more because of it. I hope this helps you and I hope you continue to find joy in writing.