Hi Moey and Welcome!
Initially my doctor knew two things about me, and we were focusing on depression and mild brain trauma for the memory loss.
After a long while, I eventually decided if I had a therapist, then I should let rip and get out the other details. I just needed that confidence with them first. They were kind of surprised. Many would not get as far as you have, unfortunately...some never get to be diagnosed with anything. They opt out and go to wherever that other place is. So you are a tough cookie, not a weak one.
PTSD remains in some shape or form, but I am sure that having beaten everything else so far in my life I will get back to a normality, whatever that normality is and the differences it may hold for me.
Right now my main concern remains with the memory loss and sleeplessness, which probably sound familiar. I could medicate, and needed to for a while, but now am trying to get through without and feel much better emotionally for it. It took a while but at the moment I am able to be there. If it takes a step back then I will do that too.
It sounds like you also have a mild brain trauma injury mTBI, especially becuase you had two accidents. Please be careful regarding something called secondary impact syndrome, ie another bang on the head could be more dangerous for you than someone that didn't have one. It would be a good idea to think about getting ready for a checkup immediately after any other bang on the head. It puts us in a higher risk category.
The problem with PTS and mTBI is first that mTBI does not show in a CAT scan, EEG or MRI in over 20% of cases, so it remains undiagnosed. I won't ever know what extent is mTBI, but the fact I couldn't read or walk properly and was picked up by security and placed in an ambulance by them suggests that I didn't only have depression. However, I remain in that frustrating place where I was told 'it's the pills', 'it's the depression' etc which I find infuriating at times. The good news is a concussion, takes a while to clear, but the brain has great powers to heal, even over the years. There is a great overlap in PTS and mTBI symptoms...common ones more specific to brain injury are forgetting names (but remembering all other details), forgetting times dates or having them confused, blanks in memory (amnesia), low grade persistent headaches, tinnitus, lack of self control, changes in behaviour emotionally or sexually.
There is some kind of retraining you can do, and I am going to look into it as time goes on first for myself, and for others coming here who have also had accidents etc. Unfortunately, I am a bit slower than I used to be on that.
In the end I gave up explaining amnesia, as the last time I saw a neurologist he realised I had depression and was taking pills and simply sent me away. The other thing is that I can do immediate recall. The problem is minor, and won't get noticed anyway. Besides, there is no pill for it, so I will have to just get on with it as it continues to improve. Memory loss though is really frustrating, so you have my sympathies on that score.
One thing that helps me is to have a paper on the exit door with appointments, when I remember to use it, as I will forget to look at a diary. I have been told to live by a diary, but found I was unable to keep up with the things to do at those times, which made me feel more useless. On rereading your post you mentioned your speech has been affected. I do not know how good or accessible your healthcare is, but wondered if you had ever been offered speech therapy. A friend of mine works in that area, and often works with people who have been in accidents. It can really help. Until I got here, I was ignorant of who exactly saw a speech therapist. It might be of use, if you are interested. Alternatively (if it's too expensive where you are or has a waiting list), I know when I was learning other languages it really helped me to record my voice reading, and listen back to it, especially if I was reading or repeating something I had recorded elsewhere such as listening to a news report sentence by sentence and repeating it back. On listening to it the areas that are differently pronounced were clear to me and I could slowly learn how to pronounce that sound in the language, concentrating on the syllable or sound that was different. It may interest you, I am not sure.
The main thing is you are now here, and doing something else positive for yourself. I have found this site more useful in understanding me than a hundred appointments elsewhere with people who are medically trained but do not give me a reference point. It made me realise I was normal, not disordered as the name indicates. You have this as a reaction to things we were not meant to deal with, that's all.