Am i overthinking or should i just give up?

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Been replying to this girl i like's instagram stories, thing to have small conversations, basically to get closer to her and maybe build some attraction(not working out tbh). And today me and a mutual was chatting, he asked me how it was going between me and her and i found out that she has been replying to his stories and not mine.

So i wonder if I'm overthinking and shes just not into me and i should give up? Or should i keep trying to get her attention etc?