My experience exactly, though the extreme pain didn't start until I was 80 miles out. I bought a factory "Comfort" seat which is an inch higher (I needed that for my knees) but uses the same firm foam as the regular seat and is no more comfortable to your tush. My final solution was a gel pad (2cm x 2cm x 2cm) inset into the seat foam and allowing re-use of the original seat cover. Gel is somewhat softer than the foam, but the real benefit is that it absorbs engine vibration which I believe was the source of my discomfort. If standard seat height works for you, the gel pad alone could help, if not cure the problem and it's only around $25 (eBay or Amazon). You can find plenty of how to do it videos on YouTube. Done properly, there's no change in outward appearance of the seat.