My best friend from high school came to visit this weekend, we had a blast. I wish he could be here forever, nothing like endless laughter!
I know what you mean. My sister and her family live in Texas and they come to visit and stay with us during the summer for a couple weeks every year. I LOVE having her here because like you said about your friend, endless laughter. I love being able to do sister things with her and just spend time together, but I also don't like when she comes to visit because I know it won't last and before we know it she'll be back on the plane going home.
I hope you feel better soon. I know how hard it is. It usually takes me a couple weeks to get out of the funk after she leaves of her leaving and then we all fall back into a routine and regular ole life.