Help please, my son wont stop smashing his head on the wall.

Okay, so my son is 2.5 yrs old. He is mostly non-verbal at this point but is slowly gaining words. So we struggle with communication all the time, I am very conscious of repeating myself, keeping calm through any tantrums and keeping a tight schedule to help him know what to expect. Also, I should add he understands what is said to him quite well, just cannot respond yet.All that being said, we are struggling this week big time. He has started smashing his head into the wall at bedtime/naptime. During the day when having a tantrum he does try to smack his head on things but I am quick to transfer him to a soft surface and help him calm down. That is easier to handle, this is hard and alot. I would think that he is frustrated or upset (ex. Not tired, doesnt want to go to bed, wet diaper, thirsty) but that doesnt seem to be the case with bedtime/naptime.For reference, this is our bedtime routine:we start out in our living room as a family, playing and snuggling.-if it's a bath night (3x a week, due to dry sensitive skin) we take a bath about 1.5 hours before bedtime-Half an hour before bedtime, we change to pajamas, he has 10 oz.. of warm milk while I change him.-we go in the bathroom, brush his teeth and hair, then play in the mirrorwe go back out to the living room, now that he is ready for bed and allow him to run off the last minute crazies. Jump on his trampoline, run around and get it all out.I give him a 10, 5 and 3 minute warning that bedtime is coming. This is so it is not a surprise and we can slowly transition.we then walk to his room, he lays down in bed with his favorite blanket. We tuck him in, give him lots of kisses, love, and beeps (nose to nose, make beeps noise)turn his Scout on to 15 mins.bedtime music, tell him we love him and exit the room.After this I head into my bedroom to watch him on the monitor till I know he is asleep. Now, up until the past week or so, he has always been great with bedtime. He would lay down, maybe coo a little, laugh to himself or play with his blankets but he would stay in bed till he fell asleep. Now, within 2-3 minutes of laying him down he gets up and walks over to the wall (smiling) and begins to smash the back of his head into the wall. When I go in to re-settle him, he laughs or smiles and just runs right back to bed. He will lay himself back down, allow us to tuck him in and then let us leave, 2-3minutes later he does it again. If I let him continue, he just hits his head harder. He is using the back of his head, but still he could hurt himself so I havent let him go more than a minute. He will repeat this for up to an hour before going to sleep. He has also now started waking up in the middle of the night doing it.I have ordered him a weighted blanket, in hopes that will help but I am really worried and scared for him. Please, has anyone dealt with this? Any ideas how to change this behavior or make it better? I am desperate, exhausted and I just want my little man to be okay. Any advice is greatly appreciated, no stone unturned.Edit: sorry for the grammar, it's been a very long week. via /r/Parenting https://ift.tt/36gaXFc