1. Try different saddles. Or sit on a Specialized dealer's ass-o-meter to get your sit-bone spacing measured so you can start closer to the right place. One which fits your butt will be a lot more comfortable (assuming you've put a few hundred miles in and toughened up a bit).

2. Pay some one for a fitting. With taint pressure and back problems you probably have issues in fore/aft positioning, saddle tilt, and/or handle bar reach/drop issues. Many bike shop employees are more interested in selling what they have on the shop floor and aren't going to get that right. Aesthetics often trump functionality (a 7-shaped bicycle stem has a look which hasn't gone out of style for most of a century, but it's unlikely to be right for you when you're faced with limited steerer tube length and the move from <= 2cm frame increments to S-M-L that mean half the people will be seated far above the head tube end for a big drop).

3. You do know that most roadies usually ride on the brake hoods? If you're struggling to keep up with a group, you might need the 8% drop in power required at that speed. You may also appreciate the help struggling to get home against a killer head wind. But out solo for 'fun' it's not going to get your heart rate up and below 25 MPH isn't going to net a full 5% speed increase (like .5-1 MPH).

4. Wear decent bike shorts without gel padding so you don't have seams putting pressure on your taint.