Hi,
Big hugs, we are going through this atm aswell. It has taken two weeks and he is getting a lot better. We have been just doing the super nanny thing of just putting him back to bed with out eye contact or talking after the first three times. the first week it took over 100 times and about 1.5 hrs untill he would crash and now it's about 5. He thinks it's a great game. As it was still taking ages after a week I started to tell him i'd take his teddy off him if he gets out again and then I follow through saying i'll give it back if he stays in bed.. that works sometimes.
We also have a gate and i use that for nap times as i find it sooo exhausting doing the putting back for over an hour during the day as well.. so i do it for a while and then shut the gate so i can have a sit down... I haven't successfully gotten him to have a day sleep, but he has for his grandma, childcare and when his dad is home

, must be a mum thing? they can sit in the room and he will go to sleep, if i sit in the room, he just tosses and turns and carries on.
I'm hoping after this week he'll stop getting up. He has stopped waking in the night which is great and if he does we can just put him back and he will stay there.
HTH,
Anna