If you feel you need a break, I would say learn some grammar and vocab before tackling katakana. You don't need it immediately anyway, especially if you know the hiragana, and there's no point in forcing yourself to do something you're going to hate. Actually putting the hiragana to practical use should help keep your confidence, interest, and general attitude up, and it's not like the katakana are going to go anywhere. Just get back to them when you're tired of not being able to read them, or when you feel ready.