4m sleep regression...

I don't think you can sleep train.

I can't train myself to sleep.

It will pass. Have you tried safely cosleeping? I found that helped.

Just take each day as it comes. I agree with Rebecca

I’d say 4 months is far too early to sleep train, they’re still so little. Try maintain some sort of routine and it will pass

Try 5-6 months for sleep training like pick up put down method, the chair method, or keep leaving the room then go in for reassurance and eventually they learn you're there if they need you. And don't feed to sleep, and once they eat enough solids move away from the night time milk. I hope this helps :)