Livesimple,
If your only thoughts were for him and his happiness, there would not be the stress arising. Perhaps the truth is you are feeling insecure, and want assurance of his caring for you? It might be helpful to realize “I miss him” and leave it at the longing. You seem to be turning that yearning into a fantasy about him.
When we love someone, we can feel insecure about whether the love is returned. So, we seek their assurance consistently. Instead, we can be the love we wish to see returned. Said differently “I love you and miss you, I hope you’re having a ton of fun.”
He’s on vacation, which can be disorienting and pull us out of routines. It doesn’t indicate anything else, that is all internal.
With warmth,
Matt