Toddler suddenly extremely attached

I’m a SAHM to a very active 21 month old boy and a 4 month old baby girl (do not recommend this age gap, just FYI)

My son has always been pretty attached to me but in the last month it has become so crazy. I take 2 steps away from him and he acts like I flew across the fucking country???? Crying, whining, throwing a tantrum.

I always tell him what I’m doing or where I’m going. I explain to him that sissy can’t walk so that’s why I need to hold her. He also wants to be carried so much more now, he’s 33 pounds and it’s just exhausting.

He’s pretty good with independent play but again he just wants me right next to him. Attached to him, basically.

I feel like I can’t get ANYTHING done while he’s awake.

Also, he is going to start daycare when he’s 26 months old and god he needs it but I’m terrified of how he is going to be.

Has anyone else experienced this? Is this developmentally appropriate? Am I fucked for when it’s time to send him to daycare??