So, I'm going to stick to the topic of depression and anxiety. That's what this is about since I see that you've asked about the risk associated with your activity and have been firmly answered that it was not a risk. So, the mental health part of your issue. That's huge. Irrational fear stems from anxiety. Health anxiety is a real thing. Yours is attached to these two sexual encounters but it is basically health anxiety. Definition: Health anxiety is an obsessive and irrational worry about having a serious medical condition. It’s also called illness anxiety, and was formerly called hypochondria. This condition is marked by a person’s imagination of physical symptoms of illness. This is what you need to talk to your doctor about. A therapist may help you. You have general anxiety as well also, it sounds. Now, I think everyone has some bit of anxiety from time to time. Few people love taking off in a plane and don't have a brief moment of 'what if'. It's normal. But does it impact you beyond that? Do you feel sick because of it, avoid the trip because of it? The extent to which it impacts you often dictates the level of care required. Perhaps just talking to someone and working on some coping strategies would be enough. Things like meditation, breathing exercises, visualization would help potentially if you are guided though doing them by an expert. Perhaps it would take more along the lines of medication. That is between you and your doctor and therapist for what the best course of action is. But DO talk to your doctor to start that process.
Depression and anxiety often go hand in hand. It can be a viscous cycle. However, to be clinically depressed, it does need to meet a bit of a criteria. One of the things doctors often look for is duration. Does it last for two weeks straight, for example? Again, how is it impacting your daily life? That dictates your next steps or treatment requirements.
I would treat your mental health like other health ailments. You view HIV as an illness, right? So is mental health issues. THAT is what you need to focus on to get better on a daily basis.