I’m 23 and my family still talk to me and see me as a child , what can I do about it?Watch this thread
The fact you made this post implies you have way more emotional intelligence than your family appear to. I suspect they are either narcissists or bitter living their own lives and thus feel the need to use you as their punching bag. You don't deserve that.
You say your family is the root cause of you feeling unconfident around others; this is to be expected. If your own family demeans you, and paints you to be unintelligent and incapable, no wonder you are feeling this way. You're merely internalising the external. I suspect this causes you a mixture of stress, anger, followed by depression.
This is a tough situation given you still live at home and seem to be doubtful of your ability to move out in the near future.
Have you spoken to anyone about this, such as a GP/friend or a non-patronising relative? If not, and you are able to, I'd strongly advise it.
I'm going to be honest, I suspect you may need some sort of therapy after you leave this kind of environment. It's essentially emotional torment on behalf of your family. Emotional torment on its own is difficult enough to come to terms with, let alone when the perpetrators are your own family. You don't have to go ahead with any therapy if you don't want, of course, I just think it may be beneficial.
If you have any questions or want to vent, feel free to send me a PM. I can try to offer some more advice.