I and my husband have been married for 7 years. We have 3 kids and I take care of them. He has a full-time job.

I do understand that he has a lot up his sleeve at work and works long hours. But I can't manage everything alone with 3 kids. So I started to ask him for some help around the house. But he always tells me that he's too tired for anything and just wants to have sex and sleep. So I started refusing sex unless he helped me around and it actually started working. Yesterday he told me that I was too controlling and this was tantamount to blackmail. 

Am I in the wrong? AITA?