I have an opposite gender friendship

so in 2024 I became friends with this girl (non Muslim) and ik i made a mistake we are not dating but I came to know that even being friends with opposite gender is also haram (unless in some specific cases and even then with boundaries).

We never talked abt dating and I didn't think more of her than a friend in 2025 alot to her from friend leaving her and so on and helped her through it all and we became even closer but still not dating and here we are.

I said all that for just a lil background now idk what to say or do it might seem like an easy thing to just "Hey we need to stop being friends it's not u its me and my religion" I cant do that because like I mentioned before she has no friends now and so lonely and she's a good friend and I cant let go and also dont wanna make her feel like used her for fun

ik that's not an excuse and I really dont know what to do

I want to obey Allah and I'm inshallah planning to do and no going back inshallah but I need help to the "how"