My dc with adhd were like this. This is how we did it:
Bring bedtime forward to take into account how long bedtime will take. Any attempt at shenanigans once in bed was met with "it's bedtime, lie down and close your eyes". Be boring. It's ok for them to be awake but they must be lying down preferably with eyes closed. Id set myself up in their room with a comfy place to sit and my Kindle. Id settle in knowing that i was going to be there until he fell asleep, however long that took. Resigning myself to it made a big difference because it won't be forever.
Every time he tried to get up id immediately tell him to lie back down - very calmly. If you get wound up, his energy levels will rise again. Everything must remain calm and quiet - if you or dh is struggling to do that, swap.
I picked out a few books (usually Mog - something easy to listen to but sufficiently long that they'd fall asleep by the end - we had all of them, so if they weren't asleep by the end of one, grab another and do that too) and as the book went on, id lower my voice, very low tone, stretch out the words, pauses between sentences, breathe deeply while reading - they'd seem to match my deep breathing and eventually they'd fall asleep. If he won't close his eyes, stroke his hair and then stroke your finger down his forehead and down his nose. Having your finger so close to his eyes should prompt him to close his eyes. Once he's got his eyes closed, he's one step closer to sleep.
I have adhd and used to be the same when i was a child, id feel very anxious at bedtime for no apparent reason but it was because i was scared of being on my own. my parents were very stern about it - get into bed, shut the door, that was it. Sleep. But it didn't work like that. Self soothing as a child when you haven't learned the skills you need is awful. My dc needed help to go to sleep - they're 8 now and they've been able to go to sleep reliably since they were 4. If they're ill very occasionally we need to sit with them to fall asleep - maybe twice a year. Once we cracked them actually going to sleep, we could start to withdraw - telling them "i need to pop downstairs but I'll be back in two minutes, I'll do one more song and then it's time to sleep". Make sure you do exactly whatever it is you said you would do. Eventually we extended the time in increments to 10 minutes and by 10 minutes, they were usually asleep. We saw progress within a few days.
You and dh continue to take turns, it's important you can walk away when you're struggling because if you get wound up, you're back to square one.
If conventional parenting techniques aren't working, try some unconventional ones. The supernanny school of thought (your child must be able to fall asleep by themselves) doesn't work for every child. Your child won't go to sleep if he's hysterical and he's not being hysterical to be naughty. He needs something , probably reassurance, and it's ok to give him it. When something you're doing isn't working, trying something else isn't '"giving in". It's just trying something else. Letting go of supernanny tactics and doing what our dc needed was what changed it all for us. Within a week or two they were going to sleep within 20-30 minutes.