Off the top of my head, I can suggest you to use some VPN.
You are right, you should not have to pay for it, but it actually helps a lot.
More over, if you're European, you are playing on a server that's in Canada, so yeah. You'd be paying for them being cheap, but it's even more worth it. Not to mention the plenty of times the infrastructure (not SE's, just the internet infrastructure) has issues, which happens quite often. A VPN often helps you avoid such issues.

Also, practicing the fight over and over is immensely helpful, and your DPS will improve as time goes on.

Plus, having a Warrior off-tank placing the combo so that you don't have to is quite helpful aswell.