What's that old saying "mind over matter"? Your brain is powerful and we have responses in our body when we are stressed, depressed, etc.
What about just not trying to link the two right now though (are the spots any better?) and going ahead and seeking intervention for the depression and anxiety? From this and yoru other post, this seems pretty plausible you suffer from this and there is help out there. Doctors are a good place to start. They can help you determine what next step to take. If medication is necessary or not, I don't know but at the very least, psychotherapy or talk therapy could be very beneficial for you. Do you have access to that?
Know that health scares don't cause depression or anxiety or everyone would get them because everyone gets health scares at some points in life. This is especially so as it appears you never had the STD to begin with. There's a very big difference between being scared or nervous because of a health problem and anxiety and depression. If you do have them, you were prone to them, and they need tending to. I have no idea if your rash was at all related to anxiety or depression. I would, though, go to the nearest best health food store and buy the best probiotic complex from the refrigerated section of the store. Two rounds of antibiotics can cause a lot of problems down the road, including recurring rashes and other problems, so you want to work on your immune system. I don't know how bad your rash was or if it got infected, but those kinds of things can be fixed by soaking with hot water until they release the pus. But you've done what you've done, and you will benefit by trying to replenish the beneficial parts of your system the antibiotics killed off. All the best.