I couldnt go up to him and smile and talk because he would have thought why is she here so i complained to him and also i felt close to him trusted him even though i didnt really know him but i couldnt help myself, i had to tell him my problems!
Guessing you are a troll but I'll reply to set the record straight for anyone thinking this is good advice. It's terrible advice. This is why some people say never take advice from women. The women who post regularly on this forum usually offer pretty solid advice in my opinion but yours is awful. If you really are a woman, then it sounds like you don't understand your own emotions and motivations.
Feelings of comfort around someone you don't even know does not happen because you are sexually attracted to them. It happens because you are NOT sexually attracted to them and you think they are non-sexually-threatening. You view them as so far from sexual that they are asexual, and hopeless, and you know you can dump your feelings on them and they'll probably listen. You use them for your own neediness.
On the other hand, when a person sees someone they are sexually attracted to, they get nervous and anxious and there is tension. They don't want to complain to them and dump on them, because that's sh*tty behavior and it will make a poor impression and drive them away.
OP, she isn't interested in you romantically but that isn't even the point. Instead of wondering if she's into, you should first ask yourself: "Do I even care if she's into me? Because, based on her behavior, would I want to spend time with a girl who complains all the time? What are the chances she would start complaining about me if we start dating?"
Hint: Avoid women who are complainers at all costs. Habitual complaining is a strong characteristic of BPD, and even if she doesn't have BPD, constant complaining and negativity points to a host of other problems that you want no part of.