A little tip to consider when designing your next character:
Your character needs to be able to survive and it needs to be able to kill things.
For fighting characters, this means you need Attack, Damage and Defense. Not just two of them, you need some of all three.
Attack: Attack is your ability to hit things.
Primarily AB but there are a few other things you can use as well.
The most obvious sources of AB is having high Strength and using a class with high BAB. Weapon finesse or using ranged weapons means you will be using Dexterity instead of Strength.
Other major sources of AB include divine spells. Maybe buffs are available to Clerics, Paladins and Blackguards to increase AB.
Barbarian Rage or Frenzied Berserker Frenzy also give a large boost to AB.
If using a ranged weapon, you could take Zen Archery and use Wisdom instead.
Minor sources of AB include taking feats, Bardsong, the Weapon Master class, Bane of Enemies or using tactics, like flanking the enemy.
There are other ways of hitting things that are not as reliant on high AB.
Stealth is the obvious one. Catching most creatures flat footed will reduce there AC.
Taunt can also reduce an enemies AC by up to 6.
A few spells and Curse song will also reduce enemy AC.
Another thing to think about is that if you roll a critical value for your attack roll, that attack will always hit. You still need to actually be able to hit to do critical damage, but a hit is still a hit, if you have damage behind it. Using weapons with high critical threat ranges, using the Weapon Master class and having lots of attacks per round will help you hit enemies this way.
Damage: Often forgotten in Dex builds.
In addition to being able to hit, you need some biffo behind it.
Easiest is again to get high Strength.
Other major sources of Damage are class abilities like Divine Might, Sneak Attack, Favoured Enemies, Elemental Warriors Imbue ability, Rage, Frenzy, Duelist Precise Strike.
Minor sources of damage include Bardsong, Divine Favour, Darkfire/Flame Weapon, Prayer, Battletide, Greater Magic Weapon, Bless Weapon.
Be aware that not all sources of damage will work in every situation. Sneak Attack is the most variable, sometimes it can do 100 damage, other times it is useless. It might be wise to have more than one source of Damage available.
Defense: It is how you stay alive.
High AC is the best way to stay alive. Damage reduction helps a lot to. But in the end your HP counts as well.
If you want high AC, a Dex build is the best option. Other major sources are to use a huge shield, Divine Shield, Monk AC or Expertise.
Minor sources of AC are some spells, Bardsong, Cursesong (to lower enemy AB), Defensive Stance, Tumble and dodge AC on boots.
Damage Reduction is another option for defense. High damage reduction means that even if you do get hit, you don't feel it much. The biggest source of this form of Defense is the Dwarfen Defender Damage Reduction ability. Barbarian Damage Reduction, the damage reduction feats, equipment choices and some spells will also help, but to a lesser extent.
HP is hard to judge how useful it is. It is absolutely vital, but if you had perfect Defense it wouldn't matter. High HP will mean you can last longer before you have to use a Heal potion. Also remember than many magics will ignore AC and physical damage reduction, so you need those HP.
Constitution is what you need for HP, though some classes get more than others, as well. If you are short on HP you can use the Toughness feats to get more, also think about Constitution improving items good equipment choices can give you up to 240 more HP at level 40.
