Hi Dawn,
I have only been playing the game for a week so I might not be the best person to answer your question but I had a similar problem. The way I fixed this was to click the shirt icon then click the tab "Wearing" it will show you a list of items you are wearing.
Sometimes there are items that cause parts of your avatar to disappear, for example, I tried wearing a new pair of shoes but the shoes did not fit my avatar's feet so it made the feet disappear, I had to "wear" feet that were appropriate for the shoes but if the avatar is not the right size the feet appear crooked, so it is possioble that this is the problem you are dealing with. Which means you will have to remove or "detatch" items from your wear list until you are left with a skin.
To adjust your body's proportions, use the same shirt icon to access your "body"
To be honest I am a little confused to the difference between "Body" and "skin" but one icon ressembles the head and shoulders of a person that is beige and brown, the other looks like two people and is blue and beige. Click on one then click on the wrench icon, this should allow you to change the dimensions of your avatar.
It can be frustrating but you will get the hang of it. I hope my answer helps you, if you have other questions you can contact me through this forum or inworld
Yours truly,
Sizzelle