Mesmer vs. Horde?
If you’re getting hit by lots of projectiles, feedback or whatever the focus #5 skill is called can help mitigate the damage while also turning it back on your enemies.
You also might look at allocating more points into toughness and vitality if possible. Glassy builds can be great at mowing things down, but they can quickly fall apart against multiple mobs if they don’t have certain other tools to compensate. If you build a bit more durable that might help out.
Or just try to pull the mobs carefully and keep them at range. It’s usually not a bad idea to focus down ranged attackers first while kiting the melee attackers.
I use Scepter/Pistol and Staff for my weapons. When faced with multiple enemies (anywhere from 3 – 5. More than that and I start pulling them separately), I aggro them all to ball them up, drop Chaos Storm on them, activate Mirror Images + Phase Retreat for 3 Clones, hit F2 shatter for 6 stacks of Confusion. Usually between the Confusion, Chaos Storm and Chaos Armor, mobs drop pretty quickly with some spamming of Winds of Chaos (traited with Illusionary Elasticity). If they still look in decent health, I swap to Scepter/Pistol, drop iDuelist, catch an attack with Illusionary Counter, then F1 shatter for more damage. That usually drops at least half of the group, and I can mop up the rest pretty easily.
This is not because I am under geared!
Lol!
You said you where level 67. So yes you are. It doesnt matter what kind of gear you have, you’re always undergeared below 80. When you got full exotic/ascended then you can talk about not being undergeared. 80 is a completely different world for any class.
In other words, no need to worry yet.
You can double tap temporal curtain (focus 4) to pull off a similar trick to the guardian greatsword, pulling all the enemies together so that you can deal with them all at once. From there you can use the sword 3 + mirror images to get off a quick 3 clone mind wrack along with blurred frenzy for some nice burst while evading their attacks. The illusionary warden can also help with some of those pesky ranged attackers. I find that builds focused on shattering can be more effective in these kinds of situation. Keep in mind, however, that the mesmer is much more reliant on traits than some other professions, so don’t expect to be as powerful as them pre-80.
Sword/Focus and Staff are probably you safest sets for large pulls solo. Staff nullifies melee enemies and focus defeats ranged. Deceptive Evasion is your friend too I recommended for leveling – its your main resource generator. Once you’re 80 and can rofl stomp anything Greatsword can be swapped in if you want a different ranged option.
So your aoe set is greatsword+ sword/focus. You want to group up mobs with the temporal curtain pull, drop mirror blade, zerker, iWarden, blurred frenzy. Most things should be dead at that point.
With regards to ranged mobs, trait your focus. That’s about it. With a traited focus, you can just ignore ranged attacks for the most part, and simply use your curtain and warden for defense.
Also keep in mind what dawdler said. If you’re comparing yourself to a level 80 guard, you are undergeared.