It's hard to tell exactly what's in your hand at any given point, but someone scoring multiple 3s off Clothing on a single action is a big deal. You should if at all possible get more colors down to block that before he's scoring 3s off of Clothing. After those first 4 achievements, he can mop up almost at his leisure.
Why did you meld Tools turn 1?
Metalworking isn't really a scoring card. It makes you think it is, but really what it says is "Draw a card without a castle. Also, maybe you get a couple points."
Turn 6, even the first City States action is probably wrong -- stealing his only red card (and it's Archery, which isn't useful here anyways) gives him another Monotheism target.