How to Trust People

Sometimes I encounter a period when I cannot trust anyone. An idea that no one actually likes me occupies me. What is the meaning of friends, boy friends and those kinds of stuffs? Some people act as if they like me even though they actually hate me. Once I started to think about this, I just can't believe anyone and fall down to a very lonely world. 
So far I was saved by a very kind ex boyfriend and a friend and somehow I managed to get out of the never ending loneliness thinking. But maybe I should get over this by myself at this stage now. I just can't rely on others all the time. Well maybe I just wanna rely on someone permanently. That's why I have a stupid dream of marriage. I do know this is a really stupid idea but I do wanna believe a marriage 'forever love' haha
As many series of talks with my friend, I realise I instantly trust people. AND people can betray me easily. Well at this point, what I consider a betrayal might not one for others since everyone has a different value. This is the tricky point.... So I try not to trust people these days but now I just don't know who to trust and what to trust with. A women I admire said 'Trust what people do but not what people say' Well I think this is kinda true. All the time, I feel disappointed by trusting what others say. Basically people can say whatever they want to including whatever they are not actually thinking. They just say it because they know it would make me happy and it would make me shut up. All the time, I believed if a person does not like me, they will tell me so directly. Well no one wants to be 'a bad person' so they won't tell me so even though I ask it. But if you just tell me what you actually think, I don't have to expect anything. 
I simply want every single person to be honest with each other. Well i do know this world is not that easy. But it's just sad and tiring to keep playing 'the game' of thinking about others mind inside, behind the words.  I like you, I don't like you. That's it, isn't it?