The world was a lot harder. So, if you're having challenges, try these techniques most experts use:
Gear - Highly advisable you seek your Waterworks Gear or at least your level 56 Crafted Gear available in Sudrilund, Wintertusk.
Deck - Do you've more than one decks? If not, maybe you should. Having more than one decks greatly helps with the enormous amount of quests we've to do. To elaborate: - Have a small deck for basic mob battles. The deck should contain a few AoE's (Frog), Blades (Myth and Spiritual Blades), Traps (Feints, Myth Traps if necessary), a couple pixies and damage enchants. Nothing else. You can toss a troll or cyclops in there if a mob survives and you don't want to waste time having to wait on four pips to build back up.
Boss Deck - The second deck should be geared to major boss battles. This deck will comprise of major hits such as Orthrus and Medusa. Most bosses are unstunnable (making Medusa useless). So be on the look out for that. Your boss deck should also contain respective shields (Tower Shields etc) alongside Treasures (TC Feint, Blades, Heals etc.) to prepare yourself for any given situation.
Pet - I can't stress enough how useful a good pet can be. In your case, one that heals, maybe provides a little damage and resistances would be ideal. If you need help in this category, let us know!
I strongly recommend emailing KI about getting text chat. I'm not sure if they will be able to assist since I believe proof of age (which is illegal) is required.
Many bosses cheat and often times, persons around talk about the cheats, especially in group battles.