I am not a doctor. But I think you should see one. If you enjoy cycling, and are fit enough to be able to ride 200 miles in 2.5 days, this kind of pain is abnormal, IMHO.
One clue is in the first sentence of your post ("...the uncomfortable seat and riding position of my bike.").
If I were you I would (a) see a doctor about the acute pain you're suffering now and then (b) see a professional bike fit specialist to figure out why biking is causing you so much pain.