well only allow them a peak. Dont let them have a good look...
Becoming concious of, and changing you expressions, will automatically make you feel better. For example, if you have a frown, sad or confused expression..become aware of it and replace it with a smile. You will notice the difference.
If you dont believe me...do it now and see for yourself.
As for not being a good conversationist...its okay. You are not expected by anyone to be the best talker. You may feel low because you want to talk more, but start with what your comfortable with.
Sure body language and non-verbal communication count for something like 60/70% of communication. So the speacking bit is only the rest and you have some language skills so your percentage is highering.
It doesnt matter if were not 100%, there is not alot of people who are 100% good at communication.
Try and not feel like you are being put on the spot every time you have a conversation with someone. Find out yourself what point are you comfortable speaking, reconigize this and only stay inside your comfort zone. From there you can and will build your confidence.
I still suggest to you like i did before, speak to someone about your difficulties. It can do more harm if your left to deal with it on your own...
Hope this helps...