Simple PTSD may completely go away and never come back. This may happen with therapy, or on its own. Combat soldiers with simple PTSD tend to expect this of everyone, so please don't go to combat soldiers for advice unless you are a combat soldier with simple PTSD yourself.

Complex PTSD will never completely go away. Complex PTSD develops in victims of chronic abuse, such as child abuse, very long/extreme tours of war, or imprisonment. Usually, if you are separated entirely from the traumatic situation, then certain symptoms will go away immediately. Such symptoms include recurring nightmares and hyperactivity. After a while, you will notice a verrrrrrrrrryyyyy slow reduction in your levels of anger, anxiety, and feelings of being inhuman.

It takes like 10 years to notice a big difference. During those 10 years, you will have cycled to a completely new set of friends. If your new friends discover your problem, they will not realize the progress you've made over 10 years, but they will just judge you because you have a problem and they don't. So don't tell people about it unless they have it too. Even therapists and doctors can be very judgemental, and most don't understand it.

The internet is a great place to start because you are anonymous here, so there can be no consequences. It's also good because you have people like me who have been living with this problem for thirty years. I won't blow smoke up your asci, trying to make you think that you only need to take vitamins or meditate or whatever. I can give you practical advice about what works and what doesn't. Where else would you find that?