Some other things to check out to increase your damaging effectiveness: have an arcane spellcaster polymorph you (root through the MM to figure out what, but since dwarves are Medium and you say you're around 9th, Troll makes a nice choice as long as you're not near civilization); have the party's arcane spellcaster cast "Enlarge" on you at the start of combat, to get an additional +4 or +5 STR (and in our campaign, if you grow 80% or more, you gain a size category and thus possibly increased reach - talk to your DM about that).
Also, if you're taking lots of damage, I'd seriously consider taking Expertise and putting a couple of BAB into AC, and if you can't trade enough that way, figure out a way to get 5 ranks in tumble and start fighting defensively (-4 to hit, +3 AC if you have enough tumble). Polymorphing into a Troll will help some, since they get a bunch of natural armor, though the Dex hit may hurt some. We play a pretty low-powered campaign (32 points point buy from the book starting at 8 in all stats), so none of the melee fighters have more than 14 Dex anyways.
A word of caution about Improved Trip, which I saw suggested earlier: it's *really* hard to get this to be effective, unless you can get some of the Polymorph/Growth stuff described above. I played a Half-Dragon Psychic Warrior with a Spiked Chain in a campaign for a while, and even with his beefed up Strength, there was no way he was going to take down a horse, or drag a rider off a horse, or trip a Troll. Honestly I'd head down either the Expertise/Improved Disarm route or Power Attack/Sunder route (sounds like your DM doesn't give out much in the way of magical weapons, so Sundering probably won't cost you much) since they're generally more effective. The other thing to consider: picking up a weapon off the ground provokes an attack of opportunity; attacking bare-handed provokes an attack of opportunity; standing up from prone does not, and being prone gives ranged attackers to-hit penalties, thus lessening the effectiveness of the rest of your team.