Dex/faith build to low dmg (need help i am new)

Hi, i recently started to play DS and just loving the game. I took a cleric whose stat are atm : 16 vit 11 att 20 end 14 str 15 dex and 14 faith. I use the astoria straight sword but my damage is really low, (i have drake sword but can only use it 2h), beating the gargoyles boss was quite hard but i did it, but now going further in game is hard with that low dmg. (Unless i am going the wrong way i killed the mini boss just beside the forgeron). So basically i want a fast melee fighter that is why i choose dex/faith build. I will be able to use DMB (i heard you have a bad invade rate with the DM conveniant so i might not go for it and use SLB instead, can you tell me if it's true?) ( i have to say i love katana and i'd like to use uchigatana 1h with a shield)

The build i want to reach is : (PVP/PVE)

40 vit 12 att¸
40 end 14 str
40 dex
8 int 11 res
30 faith (i don't know is it's worth to drop end to 30 to get faint 50 at sl 125) tell me

So my question is when am i going to be able to use another good weapon 1h with shield ? How much more dex do i need to put and should i use more str ? What can i do to up that dmg so i can move foward easily ?

Thanks a lot P.S: If i don't go for DMB would it be better to start a pyromancer and go for CMW instead or SLB is has good ?

thanks a lot for that answer ! I have two other quick question for you.

1. Can we sell useless equip in the game and how ?

2. Would it be worth gettin 50 faith instead of 40 end (going 30 end) ? What would be the pro and cons of this ? (I was thinking of getting WoG, SLB and maybe DMB not sure ...)

After 40 on any stat really (except for endurance) you really get a diminishing return on the amount of stat increases you get versus the amount of souls your paying for it. The only reason you would want 50 faith is if you wanted to use the sunlight spear

thanks and re-thanks last question now !

1.So is sunlight blade as good as Tin crystalization catalyst cause i might not want to go for DMB since it's seems it as a pretty bad invade rate?

2.What is the miracle that make you a nice armor to all magical thing ?

thanks again !