Nice shot, the comments already made notwithstanding.
I have the same problem with horizons sometimes, and that's with a camera that superimposes gridlines in the viewfinder! Too busy focusing on the subject, I suppose. You can always straighten them out in post, although, like many things, it's best to get it right at the time of capture.
Same goes for the converging vertical lines, but unless you do a lot of this kind of photography, a tilt/shift lens may not be practical. You can compensate for it some in post, using vertical perspective controls. Again, not optimum, but can help a lot if used judiciously.