Sleep/self soothe

I’m trying to get my 7.5 month old to put herself to sleep. Once asleep she sleeps 12 hours straight. Currently she needs me to rock her to sleep but if I don’t hold her long enough before putting her down her eyes immediately pop open and she screams bloody murder. I’m sick of these stupid blogs saying put her down groggy or wake her up as you put her down. I’ve tried! She will scream until she’s in my arms again. Tried controlled crying where i leave for a few mins at a time. Nothing works! After 3 or 4 hours I give up and end up picking her up. Any other practical advise? Spending 2 hours every night putting her to sleep is getting ridiculous