Hi! I'm so sorry you're going through this, but I want you to know that there is always a way to get to where you want to be.
I know it's difficult to do, but try not to worry yourself too much about getting your grades back because there is nothing you can do to change it now, but if the worst case scenario happens and you don't get the grades you want, then there are always ways to get any help and support that you need going forward.
Two of my friends from Sixth Form missed out on their grades, one to do medicine and the other to do biology at uni, so they both had a year out, where they worked and volunteered, and now they've both been accepted into really good unis and are starting in September. So grades aren't the end of everything.
And I'm sorry that your mum is pressuring you into a degree that tends to lead to making a lot of money, but you should know that there are so many opportunities in so many different degrees to make money. I have just finished my first year of a history degree, and when I told everyone that was what I wanted to do, they all told me that there are so few well-paying jobs for history graduates, but since I've been studying, I've found out just how versatile the degree actually is, and in fact there are so many opportunities that it will hopefully give me. So I would suggest not to go for a degree just because of how much money it seemingly makes, or if you need to go for one of these degrees, try to pick one that you do have an interest and enjoyment in because it will make the whole degree so much easier. I considered doing a law degree because of the well-paying positions, but now I'm so glad I didn't because history is my passion and I am really enjoying it.
But if you need anyone to talk to, feel free to message.