What should i do now?, 😔

I met a girl on an application weplay, we started talking related to studies n all from there we quit that app and went to telegram and then whatsapp we exchanged our contact also so slowly that chat converted into a hourfull conversations like 4-5 hours but but slowly she started liking me i was just there coz I find this girl very ambitious but very emotionally vulnerable I supported her gave advice that she must talk to parents dont live alone in her house talk to everyone its good she felt good with my advices i supported her in her decisions i try to heal her if she is worried about something but she started loving me and then told me that is this a situationship then plz make this tell me which you are hiding tell your feelings i said no i respect you but its not that love kind of then she said then why are you here if you cant love me she started crying on phone then i said okay okay i like you she said only like i said yess only like she felt happy then slowly she started asking me for lets marry kind of joke on some future situations that if we will marry then we will do these things but now she extremely feel for me when i dont talk to her even i have work she is heartbroken and cry infront of me and force me to say i love you and if i refuse then she say get lost you bloody idiot leave me on my conditions and at this moment i cant see her likw that so vulnerable i am confused why is so not ok when i am with her she is happy laughing and if i am not there she explain me that she feel like hell what to do i am in second yr of graduation and she is just after her 12th boards but she dont give a ** to other boys and also she is academically n personally intelligent but why such things i dont know whats should i do to free from this ?