Control & restraint injuries

Bit niche but if anyone has any info I am all ears, I was injured due to mandatory (annual) C&R training I was training to be an assessor I got injured during the session to a point I am totally unable to work, my biggest mistake was leaving work that day stating I was fine (I took loads of painkillers to get through the last hour and sat and watched the rest of the session) I then drove home and when I woke up the next morning I was unable to get out of my bed, but because I did that and left before filling in the injury at work form (anyone that knows C&R knows that your usually told if your head/arms and limbs are still attached “it’s not a proper injury” ) they say it can’t be proven it was them who caused the injury, 

I did eventually fill in the injury form once I was fit enough to move.

everthing else I could possibly do has been done now but two lawyers are saying they can’t do anything but I feel like I was a very active working and sporting person before this injury and now I’ve barely moved for a year, surely there has to be something that can be done ANY HELP GREATLY APPRECIATED IM IN A BIG HOLE!