Love issues. She likes you or not?

How to tell a girl that you love her. I love my best friend, but I don't know whether she loves me or not. What signs does a girl show, whether she likes you or not? I don't want to ruin my friendship with her. But at the same time I love her. We have been together for 8 months now, and I have feelings for her. Please guide me specially females, I would be grateful to all of you. I don't want to loose her cause she is my biggest support system. My parents passed away in April in due to COVID, i dont have a brother or sister, my girlfriend broke up with me now she is the only one I have in my life. I would request each female doctor to help me out, doctors can understand their people well whether psychologically or emotionally, that's why I want your advice. He talks to me and shares everything with me and I love her so much, I am madly in love with her and I wanted to marry her.