I know exactly how you feel. This is a constant state of fret for me and it's such an empty feeling. One thing I've done is save the texts the person has sent to me in the past and refer to those when I feel this way. Another thing is if he's been sick just text him a quick "Are you feeling better?" that isn't bugging him by any means. I do have to say that these feelings of abandonment consume me and I can't concentrate on anything but thinking why this person hasn't responded to me...but...99.9% of the time it was nothing and that person got caught up in "life". I'm a "it's all about me" type of gal so I always have to remember that I'm not in the fore front of everybody's mind. I hope this has helped a little.