Wow I am so sorry for all of your stories, it seems we all have been through a lot on here.
I also have an injury which took me out of running, something that was a part of me for a long time. I have finally let it go and no longer hope to run the distances I used to, actually, I have finally got to the point where I am no longer upset if I would never run again. I've also recently gone through a lot of life changes for the worse; my health, my physical locale and my living situation, my husband's attitude to life and work since our move, all in addition to being the sole caretaker for my ailing mother who lives 10 hours away. I have had a hard ride the past 3 years.
I will say that lately though I have begun to "accept" this new life as my own, instead of pining for the life I had prior to all this. I have started to do a lot of clutter clearing, throwing out things from my "old" life, I have started doing some yoga, looking into Qi Gong, I have been getting acupuncture, and have been attempting some breathing meditation. Because of this I have started to feel more grounded and able to accept my situation as it is, and have kind of "let go" of my old life (the one I had kept fighting to try and get back) and am for the first time starting to slowly look forward a tiny bit, instead of constantly looking back.
Change is hard, I have always had a big problem letting things/people go. All we can do is go day by day and make the best of each moment we have.