Confusion about Breaststroke

I have been swimming very irregularly recently. For 2 weeks, I've been swimming one day, then not swimming for about 2 or 3 days straight, then another day swimming, and another 2 or 3 days of rest. This is mainly due to the homework load. So, something weird happened. For the first week, I was going smoother than I had ever done when I was practising regularly, and I could feel that I was faster. I had a higher turnover rate and still managed to do lengths with fewer strokes. My strokes felt awesome. Then, the second week, it was the very opposite. I started feeling like my stroke was falling apart, and it began to become non-smooth. So, why did I swim better the first week? And also, why did I suddenly swim worse the second week? One more thing: I'm confused about the stroke mechanics of breaststroke now. Due to extremely unluckiness, I chose to start practising the hip moving-forward movement and the arching-back-force-transfer 2 weeks ago. Well, now, because of the 2 week episode, I feel all strange. Right now I'm either swimming a high-amplitude wave breaststroke with head up and arching and hollowing back, or a low-amplitude head-down style. I couldn't incorporate the body movement into my low amplitude breaststroke, and I couldn't do it vice versa either. So, can anyone please tell me what the correct body movement of breaststroke is? And how I can practice to achieve that? Sorry for the long post, and thanks for any replies!