Feeling overwhelmed with my 2 1/2 year old. Ugh

Angela
Lately my son has been fighting me on everything. He has stopped listening and when I ask him to do anything his response is NO. I am 13 weeks and have been fighting all day sickness. I am so overwhelmed and wonder how am I going to take care of my son and a new baby. What have I done wrong? Why is he acting like this? I am a stay at home mom and he only pulls this crap with me. Feeling so overwhelmed.