Is it normal to not trust anyone and feel completely alone?

Everytime I figure that if I open my heart and allow myself to respond freely and in the moment I will become closer to other people and others can tell me what they think about who I truly am. But I am so terrified of people judging me and possibly leaving me that unless I'm discussing a happy or relatable conversation I tend to keep very quiet.

Don't get me wrong, (and maybe I just forget this next part), I have friends, and I have people that I believe I can trust and can be myself around. however many of these people seem to be trusting and reaching a larger group of people than I am and I feel different from them and unable to talk with them about this.