In a similar situation of getting numb, but I get numb at 30 minutes. Fairly new to riding, but after 4 months of 80 miles per week, the 30 minute hasn't changed...
One exception, I rented a bike on vacation and numbness didn't begin until the 1 hour mark. But different bike, saddle, etc.
So the question is where do I start? Local bike shop blew me off when I asked to be fit last fall. They showed me a few $$ saddles and never mentioned a professional fitting. Fitting first, then start trying different saddles?