How to deal with toddler tantrums?

My child is is four and will go in a room to whine or cry as loud as they can and as long as they can until you go in there. I’m trying to get my child to break this habit. I’ve gone in there to comfort my child many times ns to tell them to come to me and talk to me if they are upset. My child will not stop unless i go in there.. so what should I do? I never told them to go in their room to cry. My kid has a play room and often goes to have independent play when I am cleaning. And usually it is fine but I recently had another child and I make sure to give them both attention but my oldest will fight unless they get ALL the attention all the time or else I “broke their heart”

I’m at a loss. I’m overwhelmed. I’m tired, stressed.. I feel like I’m drowning and my husband works really late nights every day so he helps when he can, but he’s never home

I really need some positive help and advice I’m how to help my oldest child with this situation