CIO/sleep training

DD is 7 months and will.not.sleep. I wish I was exaggerating when I say she wakes up 7+ times a night for nothing more than to be rocked back to sleep.

She also doesn't nap, if I'm lucky I'll get 20 minutes, twice a day for naps in her crib, otherwise she relies on napping in my arms.

I'm at a loss, I know she's not getting anything close to a healthy amount of sleep (and neither am I at this point). I'm a single mom who needs to work but I barely function anymore.

What are your thoughts on CIO? Are there any other effective methods I can try?