In reply to Fickalli: Allow me to translate.
I don't know what I want = I am dissatisfied.
That dissatisfaction could be with you, her own life, or she genuinely may not know. If you're lucky, she's not a child and if you talk to her nicely, she may be able to discuss it with you and you'll both know where you stand.
If she messes you about, don't make the mistake of staying. Walk.
Caveat being if you've been together more than a couple of years.
In every longer term relationship your sort of mildly fall in and out of love at various times depending on how busy you are, taking each other for granted etc. I was with one partner for ten years and it happened twice in that time, each period lasting a few months.
I don't know if I want to be in a relationship almost always = I don't want to be in a relationship with YOU, except when dealing with someone who is quite focused on a particular goal which you're getting in the wya of,even if only because being with you takes some of her time away from that goal.
My tried and tested method is a couple of nights getting horribly sloshed, then arrange to be really busy with hobbies etc. You'll be right in no time.