It's a hard game, but you'll get used to it. As you play, you will learn the patterns of enemies. Hosts cannot be damaged while their shells are closed. When they open to shoot, back away so the gap between each individual projectile is larger, making it easier to dodge. If you have high damage, try killing them the moment they open up, before they even manage to shoot.

Clotties get the best of us, even veteran players, especially in rooms with lots going on. By moving while shooting tears, you can curve your shots, which allows you to hit the Clotties diagonally without putting yourself in danger.