God made it clear we’re not to engage in sex out of wedlock. He made it clear not to commit adulterly. He made it clear not to engage in homosexual activity.
Now, HIV and STDs are not God’s punishment, instead, such things are WHY God said not to engage in teh above.
Think of it like this: you want to jam a fork into a power outlet to see if you can see your skeleton like in the cartoons, your father tells you not to do it, because it will hurt you, instead, you ignore him.
Now, was it your father’s wish that you get electrocuted? Was the current that passed out of the socket, through the fork, and into you of his doing? Was it his punishment?
No.
God tells us not to do things for our own good. In regards to the diseases out there, it was humanity’s sinful perversions of a sexual nature that created these diseases, and now many innocent people suffer for it. God knows biology better than any of us. And from what some scientists think, HIV came from eating monkies. Likewise, innocent people will suffer because of the sins of others. If I shoot up a bank, it is my sin, but those people I shoot will suffer for it,
Long and short, not God’s punishment, but He knew what would happen and warned us against it.