Take a ruler or piece of paper/ index card and cut it to match your sit bone width of 150mm. Then lay it across any potential saddle you might buy to see where your sit bones will land.

I followed the Specialized BG measuring advice (mine was 130mm) and the guide called for saddles at least 155mm or more. What I found was they were still too narrow at the sit bones creating the same perineum pressure you experienced. When I took a card measuring my 130mm width and laid it across a suggested 155 saddle my sit bones would land on the outer edges pushing everything else into the perineum. This problem is worsened for clydes (I'm 210 lbs)

Using my card template 130mm long I found it took a much wider saddle allow the sit bones to not land on the edges. It might look odd on a road bike but you may need close to a 200mm saddle width.