i need a sorting hat for my thoughts

I wish I knew where the switch to my 'faith' button was. Faith in God, faith in myself, faith in others. Because I'm scared. I'm scared of this growing negativity creeping into every crevice of my heart, my mind, and my soul. There's a saying, "I think, therefore I am" and the thing is, I'm not happy with the person I'm becoming. 

I smile to make myself happy. I don't smile because I'm happy. The only convincing hypothesis I can think of is that maybe,  deep down, I have this twisted belief that I don't deserve to be happy. When I started believing that lie, I don't know, but despite knowing it's a lie, I still can't help believing it and acting on it. And I hate feeling this wretched when I have no reason to be. I who have not lost a great love, I who have not suffered unimaginable loss, I who have not experienced unbearable pain nor depravity, I who have more than many others can ask for. It's baffling, even to myself that I can contain such unfounded melancholy. I'm bringing this upon myself. Somehow I'm choosing to feel this way. Maybe because it's times like this I feel so in tune with myself - because the emotions are so acute, I can't help but pay attention. Whereas, most of the days, I live, on moderate, middle ground feelings. Never fully happy, never fully sad. 

The other thing is that I expect too much of people when I know, I, myself can't do the same for them. And I hate this unreasonable side of me because it just engenders frustration when I follow the script for social interactions. It's very selfish and stupid and there have been instances where friendships failed because of that. And even when I tell myself that I should not expect much, I still do, and it just leads to disappointments (which wouldn't have been disappointments in the first place if I just learned how to accept and not expect). I unnecessarily set myself up for disappointment. Paradoxically, when things become too real for me to handle, I'm the first to back away. Human relationships are so peculiar, difficult and unpredictable. Or maybe it's just me. At this state, I wouldn't want to be in a relationship with me. Haha. 

I need a conclusion.