Check your pulse every morning, first about 30 seconds after you wake up but haven't got out of bed, and then about 5 min later. Check for your beats over 15 seconds. You'll find a trend, if the two numbers are far apart, or if they are higher then normal take the day doing light workouts. When the numbers drop back to normal then start riding hard again. This is a more long term solution. In the short term take three days and just do light workouts, and stretching, don't stop working out just do it lighter. Take walks or something. Hot baths, and saunas are good but I have never found that they "fix" me, just make me happy.
I would definitly ride the next day after a long hard ride. make it like a really easy spin, HR under 60 percent, just get your legs moving a bit. I'll feel awful, but its helping you. Its important not to push on a recovery day. then take the next day off, and your legs will feel pretty good the next day after that.
edit: I just reread your post. its 112 miles in a week, not one day. If thats a high weekly mialge for you, I'd take a day off, then go back to your old milage and work your way up, adding 10% a week.
112mi in a week isn't a lot...if you're used to it.
I do understand how difficult it can be at first, though. I remember when I first started riding, I had a hard time doing 50 miles a week and would take a wednesday or a friday off from my commute. Generally, if I'm feeling wasted, I'll take a day off. If it was really brutal I might take two days off.
Hot showers--or if you're really hurting, soaking in a hot bath--do help, at least in the immediate term.