Bedtime

I’m at a complete loss. Our little boy has always been an amazing sleeper but the 18 month sleep regression hit us hard. We’re going on 6 weeks now of toddler battling us at bedtime, won’t sleep if we aren’t there, waking up numerous times a night etc. when he used to self soothe and sleep through. We’ve tried to leave him in his bed to settle himself on a night time as normal, however he is standing up and banging his head off the top bars of his cot. So we obviously cannot leave him to try and self soothe when he is banging his head as he’s going to end up seriously hurt, but we need to start getting him back in the habits of his healthy sleep routine. Does anyone have any suggestions? Are there crib protectors we can buy that are good? Is this a sign that it’s time for a floor bed? Honestly any help is appreciated. Little boy is 20 months old for reference