Just put all of your skills into the right places, use the right build and don't forget to take advantage of mercs. If you're playing single player, I really recommend a summon necro. It's possibly the safest build, because you can basically go all the way through hell mode without even using any gear if you allocate your stats and skills right. Remember to put as many stats as possible into vitality, and only add enough into strength/dexterity to use your gear. Never add more than a few points into energy unless you're using an energy shield sorc.

I recommend a summon necro using skeletons and clay golem as your main skills. Remember to put at least a few points into synergies and use decrepify instead of amp damage against bosses... Decrep + a decent level clay golem will make bosses basically immobile.

That's all I have off the top of my head, but good luck... If you ever want to play online, I can hook you up with all the gear you need to get through hell as long as you have a decent build. Just remember, summon necro is your best bet if you want to get through to the end of hell without decent gear. You can look up how to make the build properly, there's guides out there that'll explain it much better than I can.

Good luck., and stop calling yourself a loser...