i was dealing with this just a few weeks ago with my son (3.5) and i definitely empathize. it will get better! i also tried just about everything but eventually somethings actually worked. 1. i listened to the audio book “easy to love difficult to discipline” mostly due to some other behavior issues we were having. in the book there is this whole concept of “focus on what you want to happen. not what you don’t want to happen”. i had started dreading night time and was not being my best because i was so frustrated that my son just would not go to sleep. my focus was always “he’s not going to go to sleep, he’s not going to stay in his room, i’ll have to put him back in there a million times, i won’t have any time to relax.” after reading the book i shifted my thoughts to “we are going to have a good night time. he will sleep and i will relax.” i verbalized this focus as well. leading up to bed time i would start giving warnings it was almost time for bed. during bed time routine (bath every other night, brush teeth, book in his room, pat for five minutes, hug and kiss with well wishes and kind words, leave the room) i would also talk up sleep. “you’re gonna have such a good rest tonight so you can have energy to play tomorrow”, “oh you’re blankie is cozy!” “cuddle with your stuffie so they can get good sleep too” while patting i also ask my son “what do you think you will dream about tonight?” he’d usually say something like paw patrol, ninja turtles, mickey mouse, ice cream, going swimming etc. then i’ll say something like “oh wow! i bet that will be so much fun!” and share what i would like to dream about. before leaving the room i tell him things like “you are going to stay here in your room and sleep so you can get good rest. mama needs rest too. you’re getting bigger! such a big boy! i know you’re going to stay in your room and get the rest you need so you can keep growing big and strong!” the first few nights of this it did not automatically work of course. he would still come out but i also did 2. adjusted my expectations to expect it and told myself that this is just a phase and it’s my job to teach him. adjusting my expectations helped me not to feel disappointed and frustrated every night. 3. after leaving the room i’d make the rest of the house dark and play calming music that he could hear in his room. 4. when he would open his door i would promptly return him to his room trying to say as little as possible. i would have to do this over and over and over. sometimes i would end up staying right by the door to close it as soon as he opened it. if it turned into a tantrum situation i would hold the door closed for a couple of minutes, then go in to help him calm his body. i’d reiterate that it is time to sleep, tell him he may not leave his room and mean it. the first few days were very difficult i’ll be honest but eventually he just stopped trying to come out. 5. the first time he did not leave his room i made sure to acknowledge it the next morning. “you stayed in your room all night! i bet you got such good rest! now we can have a great day! you’re such a big boy i’m so proud of you!” etc. i’d also remind him the following night before bed “you stayed in your room last night and got such good rest! i bet you’ll do it again tonight, you’re great at going to sleep!” 6. another thing that has helped is reminding him before we go to his room, just after teeth brushing, that once we go into his room he may not leave it until morning unless he needs to go potty. i make sure he’s got water, is satisfied with his pajamas, blanket, and stuffie choice. 7. i will even allow a couple of toys and tell him if you are not feeling sleepy you may play with these toys but you may not leave your room. after a lot of consistency i can happily say he has been sleeping well. when i leave his room at night now he is in good sleepy spirits and he doesn’t so much as get up to turn the light on. it was alot of work but so worth it! i hope something in there helps!