Trying to keep your squishier characters (which is likely to be all of them to begin with!) out of range of melee big hitters, or what feel like big hitters to a level 1-2 character, very much helps to begin with. The game will try to give you hints, eg with the intellect devourers in the ship to keep at range.
Perhaps some good news for you is that with the full release there will be an easier "Story" mode that might be more to your taste, especially to begin with. Or perhaps by the time the game comes out properly you'll have got the knack and be playing on the hardest Tactician mode
