How do you tell someone that you no longer (platonically) love them the way you used to?

That when you've been friends with that someone for about three years and you feel like everything has gone stale and suffocating. That when you leave her and choose to spend time with someone else, it feels like a breath of fresh air, like a window of a stifled room that has just been opened. That everything that has connected you two together is now everything that is pushing you away. That familiarity breeds contempt. That every vine that has tied you guys together has now rotted away, leaving nothing but distance between the two of you. 

That when you guys talk, it's really just you trying to steer the conversation somewhere and getting lost. That her curt and blunt replies only cage you in further and you secretly wish to break free. That you no longer share the same interests and common topics with her. That you know her too well until there is nothing left to say other than meaningless small talk. That when she cries, you really wish it wasn't you she trusted so much. That when she leaves, you feel both guilt and relief pounding on your heart's door, because you think she doesn't deserve someone as trashy as you, that she deserves better. That she is a good person and she shouldn't stick around someone as terrible as you are.

That you still like her but not in the way you used to. That growing up has made you grow apart and that things have changed but you don't know how. That you still want to be friends and you want to salvage whatever is left at the end of this.

How do you tell someone that you think everything is falling apart at the seams and fading away?

((please help me))