This is a fair question and a good one. First, you don’t get to go back to the “old you.” You must decide to live with the new you and these new complications; what we call “the beast” in here, this forum.
3 years is still very recent so no need to make yourself more angry and depressed thinking it will never go away. You gotta accept this is your new reality before you can live with it. Try to stop or decrease the time you feel guilty about what you could've done, wishing it was different and just know it is what it is now. People change regardless of what they do, war or not, so you have changed. It was gonna happen. For us, the sooner we accept it the stronger we will be. Accept, decide to live with it, distract, cope, etc. Start making the “baby steps” already referred to by others. You cannot “fix” this thing all at once. There is no cure. You have to decide to live with it and then learn to live with it.
You can deny this but most of us need other humans around, probably not at first, since we tend to isolate right away, but if you still have family around focus on them. If not, try to find a battle buddy, or several, or at least an animal companion. Group therapy can be a good place to find the camaraderie we miss from the military.
Combat trauma is on a continuum and has its own cycles; life is about cycles. Everyone has different phases. Some people have much worse complications than others but I can guarantee trying to be the most f*cked person in the room is not a title you want. So don't get trapped into "bragging rights." Start bragging about what you have "done right." Flip what you focus on. Some people just have it worse than others and some periods in your life are worse than others. And just when you think things are going well; expect another frontal assault from the beast. As you build coping skills, over time these frontal assaults will become hits, first big than smaller.
How do they become smaller? They mostly don’t but your REACTION does. You need to realize you drive your own life, your own “bus” – so you decide who, what you let get on your bus. You learn to avoid triggers, use different coping mechanisms and distract yourself when you feel the rage coming. You start to understand and adjust to the new you. That is partly what you are struggling with now. Be careful about work. If it is toxic than you should seriously consider finding a new occupation or going to school, neither of which is easy so be prepared, but you got to deal in some way with what is causing you additional anxiety.
Many people use medication, especially early on, but it is just another tool, not a cure. Meds can help you get a handle on things, specifically "a thing." They can help you deal with some tough symptoms, like getting that very important sleep. Getting no sleep is devastating for our coping ability & health so it has to be a priority. What you cannot do with medications is allow the system, some moron(s) you hardly know, simply issue you a list of meds. Someone has to manage it and the best person to do that is you! Otherwise, you might allow others paint you into a dark corner. This forum is very helpful with people discussing meds. You practically need to become your own expert so you should try to learn something about them. Dealing with different docs, don’t think they are really checking your entire med list. Find other options, holistic options: working out, hiking, massage, acupuncture, whatever…self-medication is not a good option.
All this takes effort and that gets us back to “baby steps.” The military spent a lot of effort teaching us tactics. You can’t win the war with one big battle, you start with planning and maneuvering for each engagement. You need to out flank your enemy and learn his tactics. The beast is your enemy now. We all learn to live with various enemies on this planet. Learn to live with this one.