Featwise, pick Combat Expertise (a no-brainer, basically ), Improved Combat Expertise (CW) and, if you consider sharing the benefits, take "Allied Defense" (FR-SS ). Heavy Armour (on a dwarf, if possible) with Heavy Armour Optimization (RoS) provides benefits for stationary defenders.
Some ranks in Tumble (5+) provide a nice synergy bonus for defensive fighting, too.
Another viable combo yielding a reasonable amounts of attacks with good AC would be picking the "two weapon attack" path in combination with "Imp Shield Bash" and "Imp Shield Charge" , turning your shield into a reasonably useful device besides its ability to save your hide.
A 10' reach weapon in combination with the "Combat Reflexes" and "Hold The Line" feats provides attacks (AoOs) on anyone trying to even approach you without care. Consider dishing in "Improved Trip" if you go down that road, the best opponents are those rolling around prone, unable to hit you.
Equipment wise - try investing into an adamantine heavy armour (may be out of your reach, financially ), while DR 3/- doesn't help much against giants and their 20+ points of damage blows, the three absorbed points really stack up against fast and light attacks.
Also, try to get your hands on items providing "blur" and/or even better, "displacement", probably the ultimate defense against high-strength driven attacks, because however hard they strikem, they still face the same miss chance as everyone. Also, these effects help very well against sneak attacks (including those from "feints" ) by providing concealment
If you can wriggle out access to "Use Magic Device", consider purchasing a wand of "mirror images", "blur" or similar
An Admantine wepaon - in combination with "Imp. Sunder" might resolve many drawn out fights more easily by proving very nice sundering power (admantine weapons ignore 20 points of hardness..... ) - no weapon = lesser or no attacks
"Smoking " ( from FR-LoD ) is a nice +1 weapon enchantment which provides 50% concealment plus some nifty side effects from a held weapon and is triggerable.
Not all of these strategies might be achievable at 6th level, but bear keeeping in mind for longer term development..
GL