I give you permission to BE overwhelmed for no longer than 5 minutes, and to FEEL overwhelmed for no longer than 10. Life is great, you are surrounded constantly by love, and even though in only 3 short weeks you're leaving the only home you've ever known your entire life, and this is really hard to grapple with - it's all going to be okay. In fact, it's going to be great.
I give you permission to be upset that you're not going to get as much time with people as you want before you leave. It's okay though, because love travels really well.
I give you permission to want to freak out because of all the boxes, all of the clutter, and all of the chaos - just don't actually freak out, you've got way too much to do for all that. It's only 3 weeks - just keep the dishes clean and the laundry done, occasionally sweep the floor, and this time next month everything will be nicely unpacked, organized, and clean in your new home.
NOW CHILL THE FUCK OUT.