I stopped breathing before i fell asleep when i was given general anaesthetic, when i was a child, is this normal?

Yes: The anesthesiologist was, no doubt, carefully monitoring your respirations - that's what they do! and would have or did assist your breathing had it been necessary. Anesthetics often suppress breathing so it's neither rare nor unexpected. Remember, you can suspend breathing for several minutes, especially at rest, without irreversible damage.