Should I have asked an aromantic advice blog instead? I’m sorry if this is the wrong blog to ask that about.
Aromantic people are welcome here!
It’s often hard to come out as aromantic, and it’s often something that’s perceived negatively by others, who don’t understand that aromantic people can love others and desire relationships and close companionships just as much as romantic people. I would try to tell her how you do feel about her- that you care about her deeply, even if it isn’t romantically; that she’s your best friend; that you love spending time with her; whatever it is that you feel towards her, make sure to emphasize that. Hopefully she’ll understand that you love her and care about her, even though you don’t reciprocate her romantic feelings.
As far as whether the two of you should break up — both of you need to decide what you want, and what you can and can’t live with. Do you still want to be with her, even though there’s no “spark”? Does she want to be with you, even though you’re not romantic? If you both want to stay together, what kinds of compromises would you need come up with to make you both feel happy, and are those compromises okay with both of you?
Basically, just sit her down and talk to her about all of it. Make sure to explain your feelings and wants and needs, and allow her to do the same. This is difficult, but essential. Then you can decide how to proceed!
Good luck! <3