Tanking Thorpe without onyxs and without healer? You're a brave man. But tbh the lack of healing might have been what fucked you up the most, and if this was your first run it might have been traumatic, but trust me if you managed to finish the expedition you're doing fine.

If you want to keep doing expeditions before trading is enabled again I suggest you respec so that in your tanking gear you have 300CON and the rest in STR, and keep aggro by attacking often. With less STR other dps (especially if they are higher lvl than you) might steal your aggro often, so you kinda need to keep attacking to keep the aggro. But you need some CON to stay alive with randoms, especially if you don't have gems on armor, and staying alove as tank is your priority number one, sometimes even at the cost of risking to lose aggro (you can get aggro back if you're alive, if you go down you lose 2 people as someone has to stop and rez you). After that it's just a matter of learning the attack patterns and know when to attack and when to block.