So i've been messaging with this HB8.5 on OKC for a while now but I can't seem to get a date with her.

It started out witty and sarcastic which I'm into. All seemed well cause she responded pretty quickly and I made clear that I like her. This has been happening for a few days and then it stopped. No response from her for 5 days so I message her if everything was OK and she said she had it pretty busy.
Ok, nothing to worry about. We continue messaging back and forth and the messages are starting to change from just witty and sarcastic to something friends would talk to each other about with some wittyness here and there. We're up to 40 something messages now.
At some point I threw in the idea of us going on a date and sketched out some semi romantic date. With some fun and sarcastic stuff thrown in to lighten it up a little.
NO response for 6 days. I had to ask my friend to translate something for me to send to here and she finally responded. (She's from eastern europe but livin' not to far from me right now)
I told her that i was going to be in town for something and we should grab a coffee. Again NO response for two weeks I haven't sent here anything during the two weeks cause peppering her with messages is not the way to go.

So after two weeks I saw that she was online and I just said Boo!
The next day she replied while I was in town. I didn't push it cause i've tried twice and got stuck so I just messaged her saying I was in town and that the city is beautiful bla bla bla. She threw some witty stuff at me and we messaged back and forth for a little and I cut it off cause my battery was dying.
Two days later I messaged her but she wasn't too receptive so I switched to reading her which worked. She opened up again even though my reading was the complete opposite :p
After some messages I stalled AGAIN! This time I was joking around about going to her town just so I can beat her in rock/paper/scissors.

I don't know what to do here... We're up to 90 ish messages now but can't seem to make any headway.
Starting the conversation back up is do-able i think but then what?

I know she doesn't like the immature type, I know she's an introvert at heart, she's online almost every day (open profile so I check with other browser without being logged in). I'm the one keeping it all flowing 70% of the time. Didn't tell me anything about her interests apart from what's on her profile.

Don't know WTF I should do now..... Any suggestion?

The very first thing I would suggest is.....

ESCALATION!

You need to start escalating things from the moment you make contact, otherwise you will start having conversations "like two friends would" (as you said). From the get-go you need to be flooding her mind (directly and indirectly) with sexual thoughts and pleasure, which lead to happiness. She will then associate these sexual and joyful feelings with you.

Another thing is how the conversation and replies were quick at first, and then they died down. This is your first BIG hint that she started to lose interest/she lost interest. I hate to say it but by this point in time, if you guys haven't met up or made any serious plans to meet up, you probably won't. I hate to be the bearer of bad news but it seems like the best thing to do at this point is move on to a different girl.

Try and cut your oneitis!! This is something I still suffer with terribly (probably always will to some extent) but you need to realize that there are plenty of girls out there who can fit the bill just as well, if not better, than this one. I recently had a flop over the net (as you know) with this sexy little thang. How did I cure it? First, I masturbated furiously. Second, I forced myself to go talk to girls the next chance I got. I did, and I got this girl's number on the bus who had the same features I liked about the girl on the net : )

Honestly though, if you still want things to work with her I would suggest a freeze-out and in the mean time go out and chat up some ladies and you will likely see that there wasn't much special about this girl you were so into before. She might contact you during the freeze-out time, she might not (that's the whole point, to force her to make contact with you; if she's actually interested). But after, let's say 10 days, you haven't heard from her and you still really feel like you want to be with her, send her a message and promise yourself that it's the last one you'll send unless she responds and agrees to meet up.

You should have tried to get her number (even SPAM if she's unwilling to give you her number yet). This is something you should try and get as early as possible, so that way you can start communicating more personally. Might sound stupid saying that texting is personal but it will make her feel more comfortable talking with you. Once you have the number (especially considering it was done online) you should call her and talk with her. Again, this makes her feel more comfortable and will allow you both to get a sense of who the other person is. If you can get her number and talk with her over the phone, there's a MUCH higher chance she will meet up with you.

Always remember, the girl is the one missing out on what you have (huge dick, nice personality, fun conversation, good vibe, etc.) you are NOT missing out on what she has. I'll say that again. She's the one missing out, not you. Keep that thought with you at all times and rejection and failure won't bother you as much as it once did. There are tons of ladies out there, don't miss out on all that's there waiting for the one who may or may not give you the attention you want.

Sorry man, but I think you missed your chance on this one. Failure/rejection is all part of the journey to becoming a PUA, though, so embrace it. You can read as many posts as you want, but trial and error will give you the best feedback, if you pay attention to it. You think Jordan was born dunking from the free-throw line? Get out there and try again!
Good luck!

Thanks for the reply bro!

I've been reading back the messages and although i did escalate it seemed flat and could have done a way better job.

Yeah i know, freakin' one-itis....
I'm not making any headway anyways so freezing her out isn't such a bad idea.