2 year old sleep regression after baby

K.A.S • Boy mom x3 Girl mom x1

Hi all! My middle son turned two in January. He was always a great sleeper, my boyfriend would be able to just put him in his bed and say goodnight and he'd go to sleep (he hasn't let me put him to bed since he was about 10 months old, but my boyfriend has always been able to). Well we moved on March 1st. And then my third baby decided to make his appearance 8 days early on March 4th. My two year old slept fine those first few nights, but once the baby arrived that all changed. He would start screaming hysterically any time we put him in his room, so after trying and trying we ended up just letting him fall asleep on the couch at whatever time he'd fall asleep because we just didn't have the energy to fight it while dealing with a newborn and also taking care of my 4 year old (he used to go to bed at 7:30 every night). After a month or so he started being able to confidently walk up and down the stairs on his own, so we stopped putting the gate up in his room as our room is right across the hall. He's still been falling asleep on the couch, but its slowly been getting earlier and my boyfriend will now move him to his bed once he's asleep. However, now he wakes up in the middle of the night and crawls into our bed. We have a queen size bed but we cosleep with our newborn (who we're trying to slowly transfer to his crib) and it just feels so crowded. He naps once during the day, lays down at 12:30, is usually asleep by 12:45 and then wakes up around 2:15ish (occassionally he'll sleep longer but I always wake him up by 3), the same nap schedule he's had since September when starting preschool. I know theres a lot of things that come into play here. Moving (and getting his own room for the first time for the time being), new baby, then preschool closing due to COVID. On top of that about a week ago he broke out in a severe eczema rash and his doctor only recommended one dose of childrens benadryl before bed and aquaphor (which I've been applying 2x a day). It is getting better with time thankfully but he's still itchy. But please does anyone have any tips to help my son sleep? Do I just need to ride this one out and do what I can until he readjusts? My oldest was 2.5 when my second was born and we moved shortly after but I was a newly single mom at the time so I just let my oldest sleep with me and my middle son slept in his crib fine so I've never had to deal with this before.