Hey guys, my first post on this forum so nice to meet you!
I have been reading about pua stuff and trying to apply them in real life for about 8 months, so feel free to use pua terms etc.
I had a thing with a girl for about 3 months. We were 'dating' even though it was not official or anything. Here's some points that I think are important:
Great GREAT chemistry, got her being alpha/using dhv etc but after time long story short she got the upper hand. I am 21 she is 18. She really opened herself to me from the beginning about past/family stuff. As a character she is moody, with lots of ups and downs (ups are great though and enjy being there for the downs) and we were together in a tough period of her life. Great sex but i get to do all the work (the upper hand thing). Don't know if it really matters but she is very good looking and constantly guys hit on her even though she is not the kind who would just fuck someone (like onenight stand). We had plans of studying together art abroad (we both applied, and even if only i got accepted we would go together even as friends).
One time she told me, she knew maybe this was cruel, but she felt i gave her things she could not give me. Another time we discussed that we could really be great friends aside the 'romance' thing.

So, last week after sex she began to cry. She told me she thought I was in love with her and she wasn't and thought she wanted but could not give me things. Later that day she told me not to get lost out there after a kind of argument. 3 days no contact the fourth i wanted to tell her something. We meet and it was awkward for some reason. She asks me if i feel awkward, i tell her yeah, she tells me she also does because i feel. I decide to tell her that maybe we will be better friends. She answers yes but she have never been that confused in her life, and maybe it would better to have a break. We both get emotional. She cries, i hug her we go outside and act like...friends. We laugh we tell silly things, a little flirting. I drive her home and she tells me she loves me as a person very much, we renew the going together aborad thing, tells me it might sound weird but she would have my babies (lol) and kisses me passionately. It has been 4 days since, the first two were bad (i missed her etc) but since then not too much. BUT i definetelly would like to be with her.

In a month i will have the decision for art university. She called yesterday and asked me something irrelevant (like to recommend a doctor for a friend of hers, then asked me how i was, i asked back and that's it)

OK. My goal is to play the part in a way that we can get back together but this time i will have the upper hand, cause i acknowledge that i had lost it. Scenario one is to call her within a week or so and just tell her the truth, not in a needy way ofc, but...you know. In this scenario maybe a surprise 3-day trip to...somewhere (we both enjoy traveling very much). Scenario two do nothing just wait and only after i know about the university i call her and we will see what will happen. Unless she calls before that and then my plan to act casual.

Worth of mention that she is in a transitional phase in her life so even though she is veeery social and good looking etc she has small social circle at the moment (even though she is the girl with like 100 likes at her facebook profile picture), she is currently working and told me numerous time she felt lonely (her sister, with whom she is very close, studies out of town).
That's it guys i apologise for long post, looking forward to your answers!

ps. friends tell me that she will call and that i should ignore, others not to let it longer than a week if i really want her because she might find someone else. I am not sure whats the right thing

She distanced herself and won the upper hand because you put her on a pedestal. I think you should back off a little, because from what I understood, you've been chasing her for a while (so no push-pull). Give her the space she needs to miss you and then chase you in return.

When I say you should back off, I dont mean just not see her or talk to her for a certain number of days. Its more important that you back off emotionally... Work a bit on yourself or do anything that helps you to view yourself as the prize again.

You also probably have oneitis. Since you two are not in a relationship, why not use this luxury to go and game other women for a few days a week? It will help kill the oneitis and might make you stop putting her on a pedestal. Dont call her in a week and tell her the truth, she already knows that, just get a grip on your emotions, fix your inner game, and create other options for yourself. Even if you dont say it in a needy way, the frame you are coming from is already reflecting neediness and scarcity. Hope this helps.

You are definitely right about the emotional backing off and work on inner game thing.
The thing I am not sure how to handle though is if she calls either because she wants to get back something of hers that I have (her diary for example) or just to talk.
Completely I-don't-give-a-shit reaction would maybe be too much and just wrong.

No you dont have to go over the top with the not giving a fuck attitude. Just dont pamper her too much like you usually do. Just pretend you are actually talking to your friend, instead of a girl you want to change into your girlfriend. And be sure to finish the conversation yourself when you talk to her, rather than wait for her to get bored. Just general things like that, do them consistently and it should help. But dont go afc chick-flick style and tell her you love her and cant live without her or something like that, at least not just yet.