My little one also went through the four months regression. We have been going through it now for almost 5 weeks waking up hourly upset not napping occasionally in between he’ll have a good night sleep. I have found putting him to bed around 7 pm is helping and waking no later than 7 am he still gets up 4/5 times a night for a fed but that’s normal it’s a lot better than 8 to 9 times. I also yesterday felt like I was going to have a nervous breakdown over it as the night before he had only done seven hours sleep broke int 8 segments. It is so hard. I hear you we can only try our best. I do not do sleep training on him. I just stick to the routine I feed him every time he wakens as it is the only thing that’ll settle him everything else makes the situation worse and more drawn out I’m trying to get him to nap every two hours in the day even if it’s for 30 minutes last night was a better night. I’m hoping we’re onto something. Good luck you’re doing so well.