How to stop feeling like I want to run away?

I'm just really overwhelmed? And it's literally only because I'm trying to plan a birthday party where no matter what date it's on at least one person won't be able to come. I feel like if I invite everyone but one isn't able to come than it's like exclusionary -- it is definitely not on purpose and I would never do that!! But it just feels bad. and I feel like everything would be solved if I just moved away...new place, new state, everything's cool and fun but I have neither the funds nor the ability to do that because I'm not a legal adult yet, plus the idea itself is kind of outrageous.