I first got into bitcoin back in May. A friend helped me set up a Robinhood account and all this time have been buying bitcoin through there. Thanks to twitter I recently found out that I don't actually own my bitcoin keys and this whole time I thought I did. Now I'm panicking. How do I take ownership of them? It says on the Robinhood website they are thinking about  giving people their own keys but who knows when that'll actually happen if at all. What should I do?