Mine just turned 9 mos and is doing the exact same thing. His ped. appt was yesterday and we talked about this a lot. Here is everything she said about it.
She said it's normal- it signals either a new developmental milestone or growth spurt coming, or is related to the sep. anxiety. She also said they wake up and remember there is stuff to do out there now, and they didn't before. So they will need you to do whatever your sleep routine is to get back to sleep if they aren't good at self soothing. (Mine is NOT.)
So the most important thing to do is NOT introduce any more steps to that routine. She said commonly parents will start trying anything to get baby back to sleep and now they have added all these steps or started doing things like putting baby in bed with them or giving them extra feedings in the night just to calm them down, and then you have to break them of those new things also. And getting them to self-soothe themselves back to sleep is important, they will gradually start to do that without needing you to be there also. I'm not sure how to get mine to do that, we are working on it. I still go to him when he cries, I can't help mmyself when he is crying and needs me. But I am trying not to pick him up right away, just talk to him and rub his back at first to see if that works. I feel your pain- mine has never been a good sleeper and I would give anything to sleep through the night.