TeniBear - my little one pinches aswell! Usually when she's exhausted and rubbing at her face she can't keep her hands away!

Nipple shields - I haven't used them but have heard if you let them have the start of their feed using them (so let down and a minute or so afterwards) then remove it and try to feed from the nipple. That way they aren't starving and flustered, usually calmer a few minutes into the feed. Hope that helps!