Here is the altitude track log for your flight:

http://flightaware.com/live/flight/A.../KSFO/tracklog

Just as you said, about an hour into the flight, your flight crew was challenged to find a smooth ride.

However, you were never seconds from death. You never gained or loss more than 100 feet of elevation. Also, those wings on the MD88 may be 20 years old but they can flex to handle way more than turbulence. That plane is a proverbial brick outhouse.

Turbulence puts me to sleep.