Introvert who wants space but is unsure of how to communicate it - help?

I'm an introverted forward-planner and I love my partner very much. But for the past two weeks he's been planning to go away tonight and stay away for the next two nights.I love my alone time and have been mentally - and silently - been planning these next few nights to myself since he told me (about two weeks ago) and this morning he wakes up and exclaims "I'm going to stay home tonight!" So now my two nights is just one night - which means I won't relax properly - usually it takes one day to start feeling less anxious and the next to be completely at ease.I know it sounds petty - but I hate the fact that I now feel anxious and want to say something. But I'm not sure how. "I need a bit of space for myself every once in a while" Makes him feel sad, then my alone time is compromised with feelings of guilt. Is anyone similar and has found ways of communicating how they want without feeling like shit?