Everything gets saved in draft and it says to wait for 360 seconds. There after the wait when I resubmit it says post has already been submitted while it doesnt appear.
You went back to the reply box by clicking the 'back arrow' or by pressing backspace. If you want to post, then go to the thread and click reply and type what you want and then post. If it is a big post, it is better to go to the drafts(https://bitcointalk.org/index.php?action=drafts - you can go here by clicking drafts under preview button) and copy it and click reply button on the thread you want to post, then paste it and post.
And, the waiting time will decrease when your rank increases. See these threads for details : https://bitcointalksearch.org/topic/forum-rankspositionsbadges-what-do-those-shiny-coins-under-my-name-mean-178608 and https://bitcointalksearch.org/topic/til-activity-does-not-work-on-precisely-2-week-intervals-interval-timings-582736 .
~~MZ~~