With the caveat that everyone is different,
@Stefan Mikes makes some good points.
I too, have had periods of Saddle Woe. Most cyclists end up having them. I note if you have a serious injury nothing is going to work well until that injury heals, so maybe you need to stay off the bike until it has healed and then start over.
So a few suggestions:
1. Get a Second Opinion on that bike fit. Ask around and ideally find a physical therapist or sports medicine PA who can either do the bike fit or can refer you to someone who can.
2. Find a bike shop with a Saddle Library where you can try many different kinds of saddles. I personally doubt this is a saddle problem, though.
3. What clothing are you wearing on the bike? Maybe mix it up a bit and experiment there.
4. Sometimes too much padding, either in the saddle or the padded shorts, can cause as much or more problems than not enough padding.
5. Generally I find the more layers between your bare behind and the saddle the more problems you will have.
6. Bikes aren't necessarily super-comfortable contraptions, and you should expect to have to gradually break in and build up butt endurance over time.
7. You say you are "sore and red" after 20-30 miles. So experiment a bit. What happens when you ride a dozen miles, take a long break of an hour or so, and then ride another dozen miles?
8. Again, you might need to stay off the bike until your injury completely heals to make progress.