No one can tell you how you should feel about something... Your feelings are always you own. It is certainly understandable to be shocked and confused about it, but good to think about how you do feel about it....which may be lots of things including feeling guilty or excited about it. I'd love to hear more about how you do feel about it. I don't believe though that you should feel responsible though about it. Guys who are choosing to bareback bottom must do so taking responsibility for their own actions, knowing that there is a risk to that.
But questions perhaps to talk about here might be what to do with those feelings and knowledge now, or how to handle yourself now...
Do you go back and tell guys who you are able to contact that you may have unknowingly had a viral load when you fucked them?
If it was very anonymous, you may not have the opportunity, and may just have to live with those feelings for a while, but don't beat yourself up about it as you didn't knowingly try to deceive them.
And then what do you do next now that you know is the big question
Do you disclose now that you know? There may be many guys on here now chomping at the bit to get fucked by you if you have a high viral load. Do you take advantage of that now while you have it, and experience knowingly making guys poz who you know really want to be? If you do choose to do that, I would suggest that you have some really thoughtful discussion with the guys first to ask them to really think about if they are ok with becoming poz, and if they have really thought it through. It's one thing to talk about it here, but sometimes another when the rubber really hits the road, and the reality of the possibility is a mere cumshot away.
Or would you feel guilty about even making guys poz who want to be?
If you realize that you really don't want to have that responsibility of knowing that you are empregnating guys with your HIV, then you may want to go back to your doctor, who it sounds like you have a good relationship with, and tell her that you want to go on HIV meds.
It is a bit of responsibility on your shoulders now that you know.