Sleep!

My little one had always been a good sleeper but in the last few months his sleep has deteriorated. Has anyone else noticed this? He will go to sleep fine for daddy but when I do it he panics if I leave and it has led to him refusing to even lay down, I think out of worry of me going?! He eventually says he’d lay down in my bed, holding my hand, so that’s what makes me think it’s a separation anxiety thing. But when I put him to bed it just looks like absolute refusal, smiling, jumping on his bed and trying to lure me into games! Very frustrating, hard to deal with. I’m so torn between wanting him to feel safe and comforted, to not wanting to positively reinforce his behaviour. I’ve always felt confident in being a mummy but starting to feel a bit useless and a bit lost at what to try. I have tried ignoring and just returning to bed (this worked for a few nights), I have tried comforting him, kissing him in his bed and saying I’ll come back for a kiss! Telling him off (very little, don’t like this approach but sometimes it comes out! :( I’ve tried whispering and just starting reading books again, I’ve tried sitting by his door, I’ve tried going downstairs and calmly returning when he says he’s ready for sleep. Would very much appreciate any tips or tricks? Or even knowing if anyone else is in the same boat?! No judgments please, have enough of that going on internally!