I have a 9 month old who has slept through from 7pm to 6:30am until this past month. He now wakes up anytime after he goes to bed, usually about 3 times during the night. I know it is the teething and developmental as he is very busy and crawling now and another tooth is just coming through now. The teething thing is on and off for months, so never rule it out, especially when something is all of a sudden happening! We just give him the nighttime Orajel and Motrin for pain and hope for the best. When he naps good during the day (he only has one nap a day now for about 2.5 to 3 hours), he sleeps the best and only wakes once. What is happening with our guy is that he can now sit up and then he doesn't know how to get back down! That's where I come in! I just tell myself that this phase will pass and it's probably worse for them than it is for us! That's great that you see the accidental parenting you did but hopefully the pu/pd worked and you can try to get back on to your routine.
Let me know how it goes.