Somebody please give me a better option than suicide

I don’t want to die, but I can’t live like this. A year ago I had a head injury. It was just a mild concussion, and I was expected to make a full recovery. Then, the unthinkable happened: before I recovered, I got another concussion, and a neck injury. This set off a cascade of unfortunate events that have taken almost every aspect of my life away from me. I can’t work, can’t sleep, can barely walk, can’t sit for more than a few minutes due to pain, and feel like I am slowly losing control over my arms and legs. Over time, things have gotten worse, rather than better, so now every day is more difficult than the last. The saddest part for me, is that a few months ago, I started to make a partial recovery. I got to the point where I wasn’t in constant agony, was able to walk a mile or more, and was able to drive a car. It seems as though nothing has gone right since the injury, however. About a month ago, I re-injured both my head and my neck (on separate occasions), due to accidents caused by other people who weren’t being careful around me. Now, things are worse than they’ve ever been. Even when they were improving, they weren’t great by any means. I haven’t been able to take a real shower or bath in over a year, due to extreme sensitivity to hot and cold, and even the slightest bump or jolt would send my nervous system into shock. I tried to focus on the areas where I was improving, in the hopes that everything would get better eventually. All the while, I seemed to be getting continually less coordinated. I’ve been to several neurologists. One suggested that I might have Parkinson’s disease, but the others I saw disagreed. The fact that it seems to be getting progressively worse, a year out from the injury seems to suggest some kind of neurological disorder at this point. I’m just not sure what, and it’s so hard to get doctors to listen. At present, I spend a lot of time in bed, because doing much else is too difficult. Even if I could regain just a little of the life I had, I wouldn’t consider ending it. I keep trying to hang on, hoping that I might eventually get better, or that some doctor will figure out what’s going on. It gets harder and harder every day though. I really don’t want to hurt my family or loved ones, and honestly this is the main reason I haven’t killed myself yet. I feel as though my situation is like being trapped in an airplane that I know will eventually crash. Do I end it now, while it’s still up in the air, or do I wait for the impact to kill me? I keep hanging on, hoping that by some miracle things will get better, but at this point, I’m not even sure if that’s realistic. Today I thought about buying a gun, but I’m too weak to make it to the store (less than a mile from my house). I tried to push myself to walk to the corner of the block, but my legs gave out before I reached the corner of my block, and I was violently ill for the rest of the night. I suppose if I’m determined enough, I might be able to make it, but at that point things would be so bad there would be no turning back. Do I wait it out at home, or do I muster the last strength I have so I have the option to end it if it gets too bad? Has anyone ever made it through something where there were no good options?