Perhaps it's your body language. You said that you feel most interactions as distant and impersonal, and whether you like it or not, you are unconciously transmitting that coldness through your body.
There are thousands of "micro-gestures" ocurring in any interaction at any given time, and most of them are outside of our control. People notice them subconsciously. Therefore, if you transmit negative things (and you will if you are in a bad mood) you are going to produce a negative internal response in your interlocutor. Especily in the case of transmitting distance and disconnectoon, people are going to feel like you are not interested at all in them, that you are dead inside or maybe a psychopath.
Personally, I try to deceive myself into feeling well befora any important interactions. Try loving-kindness meditation and/or use visualization.
I hope this can make better your social life.