Mom guilt starting to set in๐Ÿ˜ž

I've been a stay at home mom ever since my mini me was born (she'll be 3 in March). My husband works long hours so it's literally her and I all day every day. I'm currently 6 weeks pregnant and for some reason today I'm struggling real bad with mom guilt.ย 
I just keep thinking, her and I are so close, what is she going to think when she doesn't get my full attention anymore. Also, how am I suppose to love this new little one as much as I love her(I feel like a horrible mom for thinking this way๐Ÿ˜•). Will she start to resent me when the baby gets here because I'll be spending time with the baby and not just her.ย 
How do you moms with more than one little one do it?ย