S.,
My God, you have to teach him to entertain himself in bed until he falls asleep. you have to set the rules, explain to him that when drak falls, it's bedtime and that you'll make sure you wake him up when day starts.
Tell him he needs his sleep and mami needs to sleep too.
This the first step. Then you have to become firm. I went through the exact same thing as you are with my now 31 months daughters. Until the age of two, i had to go from one bedroom to another to pat their back, sing all the stuff sometimes for up to 2 hrs. which meant, i had no energy during the day. I was exhausted. So, I decided this was going to end. I put them in the same room, told them it's bedtime, talked to them but before leaving i said do not open door. It's bedtime. So they play a bit in their room, talk sing and fall asleep. Which is fine by me. I don't need them to fall asleep instantly, as long as they're staying in their bedroom
good luck
vlora