I am having a hard trouble with being alone.

I was alone for eight years and it was not a big problem. Now, not yet four months since my boyfriend and I have been together I feel loneliness - and apprehension. My boyfriend is out of town this week and I am hating it. I really miss him and feel lost in loneliness. I am also quite anxious. I am far more edgy and I am feeling quite vulnerable; a sensation new to me I can't quite describe. I was actually afraid last night. I brought the dog into the bedroom with me and turned the tv on loud in the living room. This is such an unpleasant sensation and situation.