Thank you MattBemis and StbGuy for your replies.
To be honest, StbGuy, your reply's really shocking to me. A small part of me do think I might truly like her now, but a large part of me can hardly see that. I have thought a few times about telling her everything, but again, this me wanting to control her comes back - so afraid I'd see she'd finally moved on and I had lost all control. Then of course there's also my ego like you mentioned, and me thinking time will heal everything (only works for a few hours and I'm back to square one. In the past when we split I think this worked only because she'd still contact me, and when I contacted her, she'd be there in an instant. Not now, however).
After writing that post earlier, I actually sent her a message thanking her for always being there for me, in a way to say goodbye, and then blocked her so that I would stop cyber-stalking her. I know facing my fears would always help, but this... it feels, tbh, so scary, and at the same time I'm afraid nothing would come out of it. What would I tell her? What would she think? When would she reply? What if she doesn't reply? What if she's already together with her new guy? What happens next? Would anything be resolved at all? And now, after writing all this, I don't know what's going on anymore. But I guess this is what you mean by putting myself in a situation with no control at all? It's so nerve-wrecking.
Thanks for sharing that song. It rings true for me too, except that part about "love". Honestly, I'm still unsure if it's love I'm feeling for her now. I'm also unsure where this side of me - me wanting to control her - came from. I come from a pretty sheltered and absolutely loving family, and went to a top school in my hometown where things were pretty neat. I do think the source of it could be from my first actual break-up with another girl, who left me because I found out she was cheating on me. From there I went online (since back then I went to an all-boys school) and decided to see what it was like going from one girl to another. I'd create a new account when things got messy and start over...until I met this ex. Again, not because I actually liked her, but because she was what I wanted back then - since she's from a different country, with this huge physical distance between us, it felt like everything was absolutely virtual and thus inconsequential (how wrong I was back then, of course).
I did have very manipulative childhood friends, however, so perhaps that could be another source too. I also really loved playing board games which I had to manipulate opponents in order to win. Maybe there's that too. And now that I think about it, whenever my mom got fed up with me and my siblings when we were young, she'd say things that are clearly untrue like, "I'm a bad mother" while crying, and if we told her she was being unfair she would say, "yeah, I'm unfair, I'm very unfair, the most unfair mother of all," and keep going on and on with how she's the worst. I don't think she was trying to make us feel guilty that way and was just trying to express her feelings, but whenever she did that, I don't know, it just rubs off the wrong way with me each time. Sure, we shouldn't have made her angry in the first place, but... I don't know anymore.
Anyway, I really appreciate you both for pulling up your painful experiences to help me. Thank you very much.

Also, thank you elin95 for this thread. It's been really helpful so far, and writing all this out, finally telling people about it, seems to help somehow too. Thank you all.