shura i'm not sure if you'll see this but if you're 2handing it you should do the opposite, max out dex and have 20 str (cause 2handing gives you 50% more str so you can compensate for it's lack, while you can't do that with dex) aswell as having 10 humanity (the damage scales with humanity for this sword). this way you'll get a lot more damage from the abby waifu ;)
you also only need 18 in and fth for this weapon