It sounds like you may need to work on your gear/skill tree as Piety in normal shouldn't really be an issue. Have you got a link to your skill tree that we could look at to see where the issue lies? Also, what skills are you using?
Hopefully this should show you my passive skills - basically fire/ice damage and critical hit chance
Not sure if there is a way to link the character to show equipment like Diablo3 had. I can see it online but can't share it from what I can see.
Think I'm at around 70dps at level 39, I've got a fairly decent (I think) wand which does a nice load of physical damage which is handy, plus has 3 linked sockets. Within this I have Firestorm (level 9) and Freezing Pulse (10) with the Mana Leach support gem (3)
I've got a headpiece which has Cold Penetration (3) and Cold Snap (10) with increased critical (10) and added lightning damage (10) linked. Can't remember it's stats though.
My main armour has Firetrap (10) and Fireball (9) with a Chance to Ignite support gem (level 7)
I've also got Frostbite and Frost Wall, no extra links there. I've got gloves and rings that add a nice chunk of fire damage (17-38).
I don't think my gear is too bad, and I'm pretty happy with my tactics, I use the wall for range control and lead enemies over traps, trying to get them to remain in the fire whilst I use firestorm on them along with other moves. I'm able to fairly regularly freeze non bosses too. The problem is I've only managed to get to Piety once without being killed by those annoying spine people due to getting stuck between other enemies
She did hand my ass to me on a platter but without trying some more I'm not sure where I can improve at the moment.
Re: the portals.... I hadn't even thought of that. I had just assumed that if I create one and then die it would vanish. I'll try it out, sounds like that should give me a decent go against Piety without having to spend 20 minutes working through the level again