Feeling overwhelmed

So I now have 4 children and I am 24 almost 25 (next month). My youngest child is 3 weeks old, my oldest is 6. So I am in nursing school I have to take micro biology this next semester and the covid stuff has been really hard. So schools are talking about not going all week and so on so homeschooling. So I am in school, have a newborn, a 4 year old who can't attend preschool now this year, a 2 year old, and my oldest 6 year old who is going to be in first grade. I haven't found my rythm yet to being a new mom of four, and now here soon I am going to be going back to school, and my oldest might not even be in school full time then my oldest son isn't getting to go to preschool. I feel like I want to RIP my hair out. I'm lucky my fiancee is so supportive but he's a mover and has long days all the time and can't help as much. I probably need to calm down, I need to breathe and relax. I can figure all of this stuff out... I just calm down I just need some support I feel...