K.M.
We went through this as well with our daughter. She stopped going to sleep easily around 9 months of age because we had taken a couple of trips, meaning she was either in bed with us or in a pack n'play in our hotel room.
My husband & I tried what you did for several weeks, and didn't have any success. She just got more & more upset to the point of hyperventilation. What we did was to just stay in the room with her until she appeared to be falling asleep. So, one of us would go take care of end-of-day chores & the other would sit in the rocker or lay down on the spare bed in her room, so that she could see us. If she stood up, we would bend over the crib side to comfort her (sometimes she just wanted to stand there & nuzzle into a shoulder - we usually made sure she had her blankie, so that she'd hopefully learn to use the blankie alone). We did this every couple hours for a few nights as well. We didn't take her out of the crib, just offered some comfort. Within a few days, she stopped standing up & screaming & stopped waking every couple of hours. Within a few weeks, we were able to return to our routine of putting her down and just leaving the room. Taking her out of the crib will just reward the behavior, so be careful not to do that unless absolutely necessary.
It will go through cycles though. Our daughter started having sleep troubles again when she started walking, which I learned is enormously common. Which makes me wonder, she's 9 months: did she recently start crawling or reach some other major milestone? That might be part of what's disrupting her sleep.
In a couple weeks, it returns to a more sane schedule. The key is offering comfort without 'spoiling' and being consistent. It's a really tough balance to strike.
Good luck!!