How can I feel so lonely after only 30 seconds of being alone?

I’ve always had this problem. Even though I generally hate people I love their company. If I’m home alone and no one answers my phone calls then within 30 seconds I feel really down. How can there be such a strong effect in only a few seconds? Is there any way I can deal with it? It’s kind of hard considering I’m constantly home alone with no one to talk to.