Whilst I hold a great respect for you, your service, and your honesty, I disagree with much of your previous comments. I agree I have been set back, but failing, failing would suggest I have given up and shall not attempt it again? To be a failure is to be someone who does not attempt something they wish to achieve and failing for me would be to throw in the towel when the mind and body is still young enough to do it. However your assessment of RM training is spot on, it is full on, and each time week 1 swings around it is difficult. But time doesn't stop, so each second passing is a second closer to my lid. Even now, I believe, I am getting closer to my lid as despite being injured, every second that passes is a second closer to a re-entry date.
I would not consider a flight regiment. It is not the standard I set myself, that is not slagging off another unit but the RM has a standard and I abide by their standard. Different units, different standards I suppose. Nor does anything else except infantry interest me. If I die in the pursuit of a green lid, as you have suggested, I dare say jokingly, then at least it will be in pursuit of something I need. If I gave up, I'd hold a lot of bitterness towards family and friends who I gave it up for last time, it's not fair on them, it's not fair on me. Nothing excites me and scares me more (in a good way) than the end role of a Royal Marine. And in regards to the fire service, it's retained, part time, I've been on and off with them for over 3 years so no drama there. They've been a great building block/foundation to achieve my real goals.
Quoting your entire comment this time given the edit at the top that makes none of this conversation make sense.
As we are being brutally honest, and bearing in mind that all I know about you is what you've posted (and deleted) here, what you write here doesn't ring true to me. You have a gap or a void somewhere in your life and you are trying to fill it and you have become fixated. You need to take a step back and do some introspection.