E.B.
Wow, what a challenge for you to be tackling this by yourself! How old is your daughter? Could she help with any of this, like taking things out of boxes and bringing them to you, or putting away unbreakable things, like linens and books?
My advice as a compulsive organizer is to start by bringing the boxes in from the garage and putting them in the rooms where they belong (hopefully you packed them that way). Forget about the spiders. Then, stack them in a corner or somewhere easily acessible and tackle one room at a time. Bring your daughter's toys in the room you're working on and unpack as she plays. If you're in a room with a tv, take advantage of it as a treat for her and put in a movie. Two hours of unpacking should be plenty for any room, except for the kitchen. If you don't think you could do a room at a time, set yourself a goal, like others said, of two boxes a day or whatever works for you. Go room by room, don't jump around, and start with what you're going to need the most - kitchen, then bedrooms, then living room, then closets.
Also, put out a laundry basket as you're unpacking and be really honest with yourself about what you need to keep and what you could donate or throw away. Try to fill it up with each room. My rule is if I didn't know it was in the box, I don't need it. My closets are so much less cluttered thanks to the Amvets truck that comes every two months and I'm so much happier for feeling purged. I think that our culture is so into amassing "stuff" that when the time comes to move and unpack it, it can literally paralyze us with the stress and helplessness of what to do with it all.
Unpacking takes time, but if you are organized and self-disciplined about it, your reward is a new, neat and comfy home for you and your daughter to enjoy. Good luck, and please do take advantage of your family's help when you can. You can do it!