Why people are hurting me so much?

Today, something really sad happened with me. All my money that I had for this trip was stolen. I know that maybe it is partly because I was too naive and because I was believing people too much over here, but in general I feel very sad.
Guys, when today I came to the Exchange office and I've seen that there are no money I thought that I will die at the same place.I went out from there and I just made an order for myself to breath, because I simply couldn't do it. There was not enough oxygen for me. I controled my breath and I ran inside of my office to talk with one more intern - Cesar about situation that happened. He insisted us to go back home and to check it there. Maybe accidently I put it some other place, but I know for sure that I didn't not. So, when I was coming home I had very different thoughts about the things that are happening around me.
After some analysis I came to the conclusion that there were only 13 people that were in our house for this period of time and that could have physically possibility to do that. After that when I thought about everyone who entered to the room for longer time I got to one more conclusion that there were only 3 people - girl from Ghana, with whome I'm stayin in one room, my boyfriend over here and my good friend from Germany. Good combination? I felt very bad about that in the same moment. This were the people whome I was believing for 100 % over here. And now I was betraid by them. I will never know who did it, because it is simply impossible to check it and also I will never have a believe to this people again, because I never will know whether they did it or someone else.
Today I had a conversation with the guy that I'm like dating here and I think that I was clear enough to tell that I can't believe him any more. And I can't continue relationship any more if I'm not believing this person, so it means that I'm single once again and it means that I'm still searching for the second part of my heart :((((
And how should I behaive with the girl that I'm living with and also with the girl from Germany? I'm totally lost in relationship between human beings. And the most important that I don't know whome I can believe now over here!