As others said...go ride some hills. The steepest hill on the route isn't far from you, and will make a great training ride. If you have a triple & a 12-25, and learn to relax, sit and spin, you'll get up the hill when you are good and ready. STP is mostly rollers. And someone else mentioned your saddle angle. If it works for you, great, but you may want to consider moving a little bit at a time to be closer to level if you have any discomfort. There is an amazing amount of good info on this forum about saddles...for good reason. Just keep poking around and searching here.