Where did I go wrong 😭

Please. Help. Me. This is my 3rd night with little to no sleep. My little ind is 9 months old and has until recently been an amazing sleeper. He wakes up 3 times a night thinking it's play time and that's just before 2am 😭 he doesn't nap much during the day... 2 20 minute naps is normal. I havent changed his routine. So why? 😭 I'm literally gonna collapse in a heap. I keep saying it's just a phase. But he's never done this for more than one night. The odd night here and there I totally get that. But I'm on night 3. I'm crabby. My heads pounding and I have no energy....surely he has to be tired... But as I type... He's sitting up in his cot shouting lalala at the top of his lungs 🤦‍♀️😭