I think I should just buy a giant padded seat.
don't do that, I think that makes it worse
One thing a lot of people aren't willing to do is to get peadal clips/shoes
and don't get the rat cage type. The biggest benifit is you are making the same pedal movement EVERY rotation, doesn't matter how you get on the bike or where your head is, foot is always in the same position...and if that's a comfortable position, that makes all the diffrence
one suggestion is
go to a real bike shop and see if they can do a 'fitting' on your bike
what they will try to do is adjut headset, seat and post so you are in the sweet position
depending on the shop, it's free or it's $200
If you buy they bike, it's typically free
Not sure why I've had little issue with this over the years and the miles, but am thankful as not sure I could enjoy it if it was painful
I think the clips are part of that