I got my belly button pierced a week ago, but the bar was to small so it started sinking into my skin and my top hole got bigger and the skin around it got lose. I changed the ring to a bigger one but now the skin is still their.Will it go down when it heals?

Did you get this done by a professional piercer? Call them! They should not have used a bar that was too small to begin with. You may have something else going on.

Did you know that the majority of people don't have a belly button that's conducive to piercing? Most have a belly button that will reject the piercing. Only a professional piercer will know who can be pierced, and who shouldn't be, and even then it's not 100%.

Doesn't sound like you went to a professional piercer. Go to them first about this issue. If they can't fix it, then ask for your money back, and realize that you're likely one of the vast majority that can't have your belly button pierced, because of your belly button, it's shape, it's depth, etc.