Some fights are definitely stressful. The dodge system is the first thing to get used to. A lot of stronger bosses and boss fights require a lot of dodging and abilities that will back you off. Bring strong heals, evasion abilities, or strong stuns.
I had a fight that I spent hiding behind an NPC that joined the battle (so he was tanking the ranged attacks for me), otherwise there was no way I would have survived.
As for groups, I have met some kind people, and if I was more social I could definitely group with them. I think I just don't feel a need to. I have my guild, and they are my buddies I run with. So these people that help on missions are at max, acquaintances. Sometimes we talk, sometimes we don't bother. Still, the game gets done, and we move forward.