Can you attach a screenshot for the same as well.
wwith horizon doesn't match do you mean that the horizon has a break in it or do you mean it is curved? In the first case, there is not much you can do. The pano stuff in Lightroom is not flexible and you can't change the image matching algorithm. You'll need better pano software than what Adobe offers. I use the open source hug in, but that has a very steep learning curve . In the second case (curved horizons) you can take the image into photoshop and use the adaptive wide angle filter to fix. This works fairly well.
can you explain or show what you mean with "the sea is a bit off?"