Hi J.,
First, I am so sorry for your news, what a difficult thing to find out.
The next thing I would tell you is that this is not the death sentence that it used to be. When you see the specialist, I am sure they can give you the stats, but people are now living very long lives with HIV. The good thing about it being caught now is that it can be monitored. I have a brother-in-law that has been positive for, I believe, over 20 years now. He is on meds and has some side effects, but overall, he is relatively healthy. And I say relatively because he really doesn't have the healthiest life style, LOL. If he exercised more and drank less, he'd be even better!
The meds are better these days, you don't have to take them every 4 or 5 hours liked you used to (in fact, many of them are once a day). And you may not even be started on them right away, I am not sure what the latest thoughts are on that. I read something recently that HIV patients are living into their 70's these days, unlike back in the 80s and 90s.
So, although this is horrible news, try not to let yourself go crazy thinking about the what ifs, at least until you talk to someone who is an expert. Keep yourself healthy in the ways that you can, and focus on the positive.
Good luck, my prayers are with you.