I am definitely struggling with the combat too. It took me like, two or three tries to fight the goblins outside the goblin camp and two tries to beat the Phase Spider Matriarch. I am not super tactically minded and don't have a lot of 5e experience, so I'm not good at exploiting weaknesses or anything like that. Most of my big combats end by the skin of my teeth after having pulled out every spell and ability I have.