I have to tell my roommate I'm moving out and I'm terrified

Any tips? I need to move out because I can't afford rent this summer (work in education and schools are out). Bonus my best friend offered to take over my lease (3 months left) because she's studying abroad and needs a place to live when she comes back. So there's a person who is willing to move in. I just feel awful for her. I own so much and this will for sure screw her.

Can't wait to have this talk tonight 😓 my anxiety is through the roof.