True Or Fake?

I feel that I think a lot when I am bathing and I have no idea why. It's like those life questions know when I'm bathing and they've decided to appear in my mind when I shower, and that's when I think too much over a particular question.. Today, the question that was stuck in my head was "how do you exactly know which friend of yours is genuine to you?" I can't figure out the exact answer, so I decided to post my thoughts here. 

Sometimes, I have no idea how to "detect" people who are fake to me. I'm NOT referring to anyone here, it's just how I feel at times, blame it on the shower. Anyway, you may think that someone is being genuine to you and that they really care for you and treat you as a friend, but is this really what is it? Some people are good actors/actresses, you will never figure out what they are really thinking inside and what's their intention of treating you so well when in fact they hate to do so.. It's like they are planning something behind your back without you knowing about it, and when you find out about it, it's too late. You just feel betrayed. Their actions can make you feel love, but somehow, I'm afraid to find out that some people in my lives are just being unreal to me, and this thought scares me. 

I don't like the feeling of "I will only look for you when I need your help on something, and when I don't, you're out of my league". It's a terrible feeling I swear. That's not what friends are for, yes, I don't mind helping you when you need my help, just don't shun me away when you don't need my help because you have no idea how hurtful your actions are.. I questioned myself over and over again to try to figure out who am I to these people who are out to take me for granted? Am i just being used? I have no idea, but maybe I shouldn't care too much about this, overall, what matters most is that I still treat these people as my friends, that's all that matters. In any case, if one day, I'm no longer there to help them whenever they need me, how will they feel?