I had the same with my daughter - now 3 years old. She was never a great sleeper, but we hit a wall at 7 months - she was constantly making noise and wouldn't go into a deep sleep. We ended up hiring a sleep trainer who went through our routine, tweaked it a bit, and then we did the gradual retreat method of getting her to sleep.
Basically i put her to bed (normal routine, bath, bottle, story, low light etc) and then she would cry. I left her cry for 2 mins, then went back in a gently said 'sleepy time' and shushed her. No picking up. Left the room (sat outside) and then left her for 4mins, went back in, said sleepy time and shushed again. Then went in after 8 mins, then 12 mins...etc
Night 1 is took an hour for her to sleep, but she slept for a long stretch.
Night 2 took 45mins for her to settle.
Night 3 30mins - and touch wood, we've been mostly good since then.
So it was 3 difficult nights in total, but it really worked.