Hey Crissy. First of all, friends are friends virtual or otherwise. The on-line experiences you have with people are valid. So is the need to reach out for comfort and understanding.
You are dealing with a lot, and are in a position where you are looked on as someone who everyone else can look to for comfort, courage, advice... That can indeed make you feel alone. However, you can't remain for long in a position where all that energy is flowing outward without some coming back to you. You do need that to stay healthy and strong. You will need that for quite some time, by the sounds of it. Do not question your need, nor your act of self preservation by seeking to fill it. You have enough going on without the added pressure of self-doubt. We are, after all, a community. And stuff like this is why communities (virtual or not) shine. OK?
That being said, there are things that you may need that we cannot offer. We can't, for instance, reach out and (((HUG))) you... hard though may we try. We cannot walk beside you that way, and I hope you have someone like that as well (professional or otherwise).
Losing someone you cared for for so long is a hard blow, as is finding out about the other situation. How helpless and hopeless you must feel! Take heart in the knowledge that this moment will soon be followed by the next, hour by hour, day by day, week by week will progress forward. No grief nor loss can stop that progress. And time is surely a healing thing. Always.
I don't know the whys and wherefors of everything, but if you cared for someone, nursed them along, for that long it implies that something was wrong for them and perhaps you can see that they are free now? (Though that will not diminish your pain, I know.) And that your family member has come to the point where this disclosure was made might really be a sign of progress for they no longer carry this burden alone. Rough though it may be, a burden shared is one lightened. And time, that all healing process, marches on for them as well.