Someone says they felt the spirit to cling to me, but I don't feel the same way towards them

So I met someone two years ago who I struggle to identify as a friend of mine,
but however they are still very clingy towards me. They message me every day, and if I don't get back to them they start to panic and cry. First few weeks I met them and talked to them, I admit she really weirded me out a few times and that's when I decided I don't want to keep hanging out with them. But they continued to message me, and I messaged them back and it just has become unavoidable.
I know I'm my own worse devil for wanting to cut contact with this person, but I'm the only person they know who actually talks to them. I wanted to help her with her life a little but I can't help this feeling of unattachment. She's become a lot better of a person since, and she's very thankful and I am glad I helped her. But still I can't keep talking to them. We had a brief sexual relationship for a while some time back, (which I still hate myself for) so a lot of this attachment is my fault, I know. But as a result, she is a reason that causes me to relapse and go to PMO sometimes.
It feels like I'm stuck. If I keep entertaining her and speaking with her, I just continue this charade of her considering me her best friend, and she places her destinity and relationship to God through me. But I don't feel the same way. She says she's felt the spirit towards me, and how she needs to be with me for her life but I don't feel the same way. When I think of staying with her, I feel dread.
I don't know if it's the devil's influence over me, or if I'm just twisted, but I really don't want that. It feels more like she's imposed her will on me, and I failed to speak for myself. So yes, it's my fault. And I accept the consequence and I also know she's probably going to be the last person I'll ever know who even cares for me on such a large level. But I can't stay. She drains a lot out of me. I know what my purpose is, and she is not a part of it. But she won't accept that. She says I'm wrong. She says 'God placed us together so that we may fight together' and language like that. She's so clingy.
I'm sorry, I'm sorry to God and I'm sorry to Her. but I can't do this. some of you may say I'm wrong and that it's the devil's influence. I accept that, but my choice to want to be alone from her doesn't feel wrong.

 

it's unfortunate that I really am her only option. but I just don't love her nor want her. One of our apostles said "the more important thing to ask for is that you'll love them, not them to love you" or something along those lines.
I'm a submissive person, and easily manipulated. When someone presumes something, it's very hard for me to speak up. That's why this situation has evolved to the stage it has.
I told her all that I feel, and although she was wrecked for a day or two she's come to acceptance of it. But she begs me not to 'leave'. when I talk to her, my mind just focuses on other stuff I have no interest to actually be in conversation with her. It makes me feel like such a awful person. she talks a lot and really fast (she's autistic and ADHD) so she has a lot of things to say, and within the course of a day she goes from feeling really mighty to really down and depressed. there's just nothing I can do and Im stuck having to care for her.

 

it's a sensitive topic for me and not one I like thinking or talking about.
I was equally needy and dependent as her when I was 17. so this just makes me wonder if this is a mirror, a punishment for me for my behavior back then.