Is this normal?

First off let me start by saying that I love my children more than anything in this world. I have a 7 year old, almost 1 year old and almost 20 weeks pregnant. I have dealt with depression and anxiety on and off since I was 16 I am now 30. The past few weeks I have been numb to everything around me. I haven’t been feeling as connected to my children as I should. I feel as though I don’t pay enough attention to them. I am happy and blessed to be having another child because I have had two previous losses…. But I just don’t feel as excited and connected to this pregnancy and baby as I did with my 1 year old (7 year old is adopted) I have been holding this in for weeks and drowning in guilt. Today I broke down to my SO and tried to explain the way I am feeling. He told me that I am a good mother to my children but now he is upset with me because I told him about not being as excited to have another baby. I am already drowning in stress from work and household duties. I work a full time job, get home tend to my kids, get them fed and cleaned for bed and then focus on the house. By that time it’s 9pm and I’m exhausted. He works overnight shifts and doesn’t help with as much as he should. I also work a part time job 16 hours on the weekends. I do not get a day off so I am exhausted daily. I tried to explain that I am feeling this was because I am so stressed with having a 11 month old child and being almost 20 weeks pregnant. On top of that my 7 year old has some behavioral issues that I am trying to get diagnosed. He doesn’t understand the way I am feeling and now will not speak to me after talking to him about the way I feel. I feel like a horrible person for feeling the way I do and I wish I could stop feeling like this.