Thank you for checking out The Baby Sleep Site! I’m sorry to hear you’re having so much trouble with sleep. Based on your comment, it does sound like your little one might be coming into the 4 month sleep regression. We have an article with a lot of information on that here: https://www.babysleepsite.com/baby-sleep-patterns/4-month-sleep-regression/
Parents often wonder how to know if your child needs sleep training or if their sleep habits are just something they’ll grow out of. If your baby is consistently cranky and overtired, it's probably time to look into helping them become a better sleeper. And as Melissa noted, she started sleep training the second time around because she could tell her son was just as frustrated as she was about not sleeping!
In the first several weeks of life, babies are hungry at night, leading to an apparent reversal of day and night and erratic sleep patterns. Fortunately, this usually resolves by about 3 weeks of age, after which your child settles into a three- or four-hour cycle, typically following a pattern of waking, feeding and sleeping. At this point, exposing your baby to natural light during the day can help encourage longer periods of daytime wakefulness and more sleep at night.
Once you launch your plan, stick to it. Parents who've been through sleep training agree that consistency is the key. Unless you realize that your child simply isn't physically or emotionally ready and you decide to put the program on hold for a while, follow through with it for a couple of weeks. When your baby wakes you up at 2 a.m., you may be tempted to give in and hold or rock him, but if you do, your hard work will be wasted and you'll have to start over from square one.
12 baby-sleep tips for exhausted new parents Before you even think about “training” your baby to fall asleep on their own, make sure you’re following a regular schedule and putting them to bed at a consistent time each night (hint: early is usually better, typically around 7 or 8 p.m.). Starting at about two months old, it’s a good idea to try to put them down drowsy but awake whenever you can, just to get them (and you) used to it, even if they fuss a bit. Make sure that they’ve been awake for an appropriate amount of time before bed (an over- or under-tired baby will have trouble falling asleep), and establish a calming and consistent bedtime routine, like a feed, bath or massage followed by pyjamas and stories or songs. Some experts recommend feeding at the beginning of the routine to avoid having the baby associate the feeding with falling asleep. Ideally, your baby won’t have started to nod off at any point during your bedtime routine. “You really want to make sure your baby is primed for sleep,” says Pamela Mitelman, a psychologist in Montreal who specializes in infant and child sleep. Be conscious, too, of filling their daytime awake periods with enough activity and stimulation, says Garden. “Kids need to be moving in all sorts of ways when they are awake, not just sitting in a bouncy chair,” she says.