Well, you may need to change out your seat... and you did that... so you might find some relief there.

I know for me, if I don't ride 2-4 days a week... when I get back on my bike, my butt is sore for days.

It's like no matter how thick the padding in the shorts are... my boney sit bones just jab into the saddle. MISERABLE.

I need a nice racing saddle, with EXTRA PADDING where my sit bones hit. I'm thinking about creating something myself. I saw where someone used some mouse pads and duck tape... and it seemed to work!