Ladies why is she doing this?

[RILEY1982]

I like this girl who didn’t tell me she was seeing someone. She knows I like her I would do anything for her. I tried to walk away from her but she said we have never spoken about our future. Or she uses the excuse she is sick she needs my help etc.

[quaranta]

She knows you like her and that you would do anything for her, but, on the other side... Does she like you and would she do anything for you? I sense not.
Don't give more in response of receiving less, never. You'd get the opposite effect, plus getting trapped under a situation where you invested too much to leave, addicted to the hope to get something in return to fix the debt in what you spent (in mental energies, dedication, availability etc). Also, this is unattractive.
If she is seeing someone, don't make her your only one. See someone you too, maybe that one will be even better than her afterall.

Maybe she likes the attention or feels guilty for your disappearance like maybe she thinks you got offended, but if she likes you then she would have committed to you, not "seeing someone else". She took her decisions, her responsibilities. Don't cling to that...

[Anonymous]

doesn't matter “why” she's doing it. Just move on and find someone good.