[rodw]

I can understand your angst, but at the end of the day you have two choices: keep going or stop.

(Note I'm considering "pivot" under "keep going".)

Not knowing what your market is, I'm still pretty confident about a few claims:

1. Most of the target market hasn't heard of either you or your competitor.

2. No customer cares who had the idea first.

3. There's almost certainly room for two different takes on this product. You're not going to be 100% the same as the competitor (and even if you are, then you're competing on execution).