Am I deluding myself?

Okay, I'm 15,000+ words (need to update my meter) into my novel, with a stated goal of reaching 25,000 by October 19th. I'm currently reworking the initial chapter, with good reaction so far. I've posted one section on the critique workshop with, again, good reaction and useful comments. I have a very well-developed sense of my MC Elspeth, and a pretty good one of the other MC Alec. I know time, place, and historical setting. I'm using historical characters and events, and researching them thoroughly. I know the main plot, a few twists, and a few other potential story arcs. I was a little disheartened last week, but after taking a break I feel fresh and ready to dive in again.

Yes, I'm writing a Scottish time-travel romance. There are quite a few of us on the forum doing so, and I think that Diana's presence there is a draw. But I don't think we're all there just writing these stories because we wish we'd written Outlander. There are a lot of Scottish time-travel books. I've been seeking them out. I read the whole 5-book series by Janet Chapman (eh, they were okay I guess), I'm reading J. Ardian Lee's Son of the Sword series (pretty good, if heavy on the history lessons), I just got Sandy Blair's A Man in a Kilt, I've read a couple of Tess Mallory's books (Highland Dream and Highland Fling) , I read a quite good new book called Return of the Highlander by Sarah MacKenzie, I have Karen Marie Moning's first book of her extensive (7 books? more?) series at home in my TBR pile, etc. And those are just the tip of the iceberg.

So, yes, I am writing in a sub-genre niche, but lots of others have done so before me. And most of the authors listed above have found success in said niche. There are readers out there who enjoy these kinds of books. I was/am one of them. If I'm gonna buy a romance novel, it's most likely to be a Scottish historical (time-travel is a bonus), or a Regency. These were my preferences before even having heard of Outlander. Diana's books just happen to be the best in this niche, so of course they became my favorites.

I said all that to get to this point. This morning I was told that the section I posted on the critique forum to be vetted before submitting it for the Surrey chapbook read "uncomfortably like fan fiction."

Now I am confused, and concerned. Am I deluding myself into thinking I'm writing the novel I always dreamed of writing, when in actuality I'm just writing an extended version of Outlander fan fiction? Even though the setting is 50 years earlier and I'm including non-Outlander-related historical characters/events and when I was first trying to come up with the book idea I deliberately tried to avoid anything that would make it seem like Outlander Redux? And I'm not saying that in sarcasm. I'm really worried about this. I was worried enough last week (while I was still in the slump) about writing in the niche that I e-mailed Kristin Nelson about it, but her reply to me assured me and I resolved to just make my writing good enough to sell.

Here's the excerpt in question: "Takedowns"

Seriously, is anyone who reads my book just going to think "fan fiction"? Do the people on the forum think that but they are too nice and supportive to tell me so? I was cautioned about it early on when I was still describing my plot in kinda vague terms, but when I elaborated and added in all the specific details (see this previous post) I was told that sounded okay and possibly interesting, if done well.

Am I deluding myself?