Change to a larger tire, 35mm or larger if you can fit them, but leave room for fenders which you will want come fall/winter. I'd suggest going to a LBS for this.

On those larger tires, you can run much lower pressures which absorbs shock better.

See

http://www.bikequarterly.com/images/TireDrop.pdf

Though I would run about 10 psi higher than recommended there, since you hit potholes a lot.

As you get more comfortable on the road, and get more familiar with the route, you'll hit fewer potholes and will learn to "ride light". Riding light means lifting your butt of the seat just a little, softening your arms and legs just a little, so that when the bike hits the bump, the bike moves freely without being jammed into the bump by your body weight. It also means lifting the front wheel just a bit when you come to the bump. And of course it means swerving around potholes when you can. On a route that you ride regularly, you will come to remember where the worst potholes are.