It is not possible, IMHO, to "get to know" someone online. It is only possible to become vaguely acquainted. An online persona is an edited presentation. Furthermore, whether online or IRL, knowing someone takes time. Really knowing someone takes lots of time.

You have an image in your mind of this person. That image is as much a product of your imagination as it is who this person really is. So you decided that this person was nice and trustworthy and someone good to confide in . . . partly because you've been needing someone like that to come along. You've been needing to unburden yourself of a lot to "someone." No harm there. You did so and felt better.

But now reality has sunk in. You don't know this person. So I'm not going to tell you that this is going to be okay. Only time will tell. Maybe it will, and maybe it won't. You'll just have to wait and see.