Very lost and scared everyone

Ladies I'm so scared. My life is falling to pieces before my eyes. I just found out I'm 7 weeks pregnant with my third child and I know that is supposed to be amazing and it was. I thought that's what I needed and wanted. I have a 3 year old and a 7 year old and me and my husband have been together for 11 years but it's turned out to be a horrible decision. We live with his mother and have for a good few months now and it's has been a living nightmare. We can't afford to move out, she is the most selfish person I have ever met in my life and my 7 year old just got diagnosed with terrets syndrome. This house is tearing us apart and I have realized how selfish of me it was to create another life when I struggle to take care of these two perfect angels I have already. I was rediagnosed with depression this past year and I don't know what the hell I was thinking. I don't know what to do. I'm so scared and I have no friends and my family can't help because they are just as bad off. I have no one to talk to and it seems like my husband just doesn't get it and I am scared I am starting to realize he is just as selfish as his mother. I need help. Why can't I be the strong woman my kids need me to be. I feel like an idiot. I have no one.