I don't know how to tone it down. 

After getting hurt very badly by someone I had a lot of feelings for (I hurt him, and he left me), I jumped back into OkCupid less than 2 weeks later because I don't know how to function if there's no romantic interest in my life to obsess over. 

Finally found a profile I really like. We mutually "liked" each other. I got all worked up. Messaged him (at 1am). Fell in love with the profile. All but memorized it. Even before he messaged me back, I:

* Found all of his social media

* Found all of his exes' social media 

* Wove a narrative about why he's "the one" (looked for stupid little clues and 'coincidences' and 'signs')

* Imagined all the conversations we'd have

* Planned out all the dates we'd go on 

And until he messaged me back the next afternoon, I was a little storm of anxiety. I texted all my friends, freaking out and rambling about how I'm going to be forever alone because no one likes me. He looked at my profile again, twice (but had no response yet). I assumed that he was just picking things to change his mind about. 

And then, finally, he messaged me back (a thoughtful and well-composed response) and I was euphoric. I danced in my office. I felt like I was on a cloud. 

I messaged back, [excited and lengthy and heart-on-my-sleeve-y](https://imgur.com/fw6zrLj). 6 hours later, and he's been online (I check back to see when he's online obsessively), and no response. I'm crushed; I feel like bawling and I can't concentrate on anything else except studying everything about him. The thought of losing him devastates me. 

Writing this out, I realize how absurd and absolutely creepy and fucking WEIRD this is. Not to mention an invasion of privacy. 

This is the worst I've been in so long. And I CAN'T HELP IT. How do I stop? 

EDIT: Thank you for the thoughtful comments. This sub is one of the most - if not the most - insightful I've ever seen. 