What to do with my girlfriend?

I have a girlfriend and she doesn't know if she love me ; I asked her out and she said yes but she never says "I love you" or " I miss you" :( Even when I say it to her she laughs at it :(. I am starting to get frustrated and im not sure if shes worth it anymore.

I was thinking of letting her go but i am not sure because I thought she was the one but i dont know what to reply to her i was hoping to tell her goodbye forever yes i know that sounds stuiped.

But my ideal scenario would be she falls in love with me well something like that but by writing a powerful text to her - So i was hoping if you guys & girls can tell me what to write i was thinking of just telling her " I guess their is no point on even trying this, its just the same thing with a different girl and i think its best we don't talk to each other anymore i am tired of doing everything and not getting any appreciation back "

so really i dont know how to respond to her text and i want you guys to helps write the best text possible

She says " I dont know if i love you"........... So how should i respond back to her

p.s I want it too be something that will really touch her heart and love me ik thats not gonna be possible but i want something close too that or otherwise how do i end it with all my feelings on the line.