Balbaroth's the best 1h/shielder I've ever seen. Just sayin'.
Many moons ago I too was a 1h/shielder, and I dare say I did rather well. My suggestions regarding equipment:
1. Don't weigh yourself down with tons of armor--you have a shield. Agility is your best friend, particularly when you're facing large groups of enemies. I've always gotten a rush from fighting 3+ people, weaving in and out of them like a ninja, rushing the people in the back unexpectedly.
2. Pick a good shield, and loom the fuck out of it. I suggest the brown lion heater shield. I used it, and it worked well. I had the pleasure of stealing Balbaroth's loomed one a few times, and I felt like god.
3. Use a variety of 1h weapons--be versatile. I've still got a small armory worth of 1h weapons to choose from in-game, which allows me to adapt to the situation on a round-by-round basis. For example, if I notice the other team's top players are shielders, I'll grab an axe and go a-hunting!
-If you have the cash, carry two weapons. I'd suggest carrying your favorite sword/primary weapon, and a mid-tier axe in reserve for shield busting. Or, switch the secondary axe out for a bamboo spear for anti-cav work.
Oh, and I very much suggest that when you are fighting you do so like a boss. You need to constantly be moving, and when you move, it must be a) unexpected and b) with determination (don't pussy foot about, pick a direction and GO). When you attack, don't spam a single direction--attack from every angle, particularly the unexpected overhead or thrust. Fight as a member of a team, and do so effectively. A shield wall, however fun, isn't always effective. Holding off 5 enemy 2h/polearm bundle of stickss who are trying to flank your team is. Helping out a teammate who's getting swamped by enemy melee and cavalry is. Distracting the other team's archers by attacking them is (you may not kill them, but they'll have to kite you and run like bundle of stickss, and they can't shoot your team when they're doing that). When facing cavalry, be awesome and sidestep as they charge toward you, simultaneously overhead slashing the horse's face.
tl;dr: NERF CAV.