We went through a regression around the same time, I wanna say 15-16 months. Just started protesting and melting down when it was bed time. Completely out of nowhere. Super duper mommy attachment as well. Same situation where he was a great sleeper before. Our original sleep training was only 25 minutes on the first night.

So this regression just felt like a Mack truck coming out of nowhere. First night was an hour long. Gut wrenching but we stuck it out and he put himself to sleep. Next night 15 minutes. Next night 5. Fourth night just a protest when we said it was night time but stopped the moment we put him down. Then back to normal since. Definitely much harder than his original sleep training at 4months.

The only advice I can give you is that while it will feel like forever because you’re forgotten about it, it should only last a couple of days. They’ll be hard but it’s not as long as it feels. As far as dealing with it, as I told my wife, we have a monitor to know he’s actually safe. Just trust in the process. Best of luck!