I am having tough time with baby sleep. 4.5 months old now and has been not sleeping after he was 3 months. He sleeps from 8pm to 7am by waking up a lot of times in between. I need some suggestions please help.

Do they sleep better after leap 4?

Do sleep training methods/paid classes actually work? If so is it better to wait until he completes the leap.

Which sleep training methods do u suggest?

I have been so stressful restless and sleepless for so many days now.