As someone who has dealt with chronic pain because of my scoliosis, the fact that you seem more interested in securing disability than in fixing your back and managing your pain is truly mind-boggling to me.
Everyone on here who has experience in the matter is saying to get the ball rolling with disability. Fine, go start the paperwork. You might end up needing it.
But you're young, you have a lot more of your life ahead of you, and you really need a reality check.
One of two things is going on here:
You have a real debilitating physical problem that will continue to cause you pain and grief unless you treat it. I went through this. Sitting on the train for 5 minutes would cause me pain for the next several hours. It was painful, made it hard to focus, made me move and hold myself in strange ways. And once it got bad, all I could think about was how to fix it. If that's the case, go to the doctor, go to the clinic, go to PT, take a yoga class. Do the exercises they prescribe even when you can't afford the copay for an actually visit. Put in the work to make yourself better. You owe it to yourself and the person/people who are helping to support you.
You have a mental/psychological problem that is causing problems for you. It might be attention seeking behavior. It might be drug-seeking behavior. If you're really autistic (and not "autistic") it might be hypersensitivity to real but less severe physical problems. Maybe you just find comfort in having an excuse for all the things you don't like in your life. If this is the case, you also need to seek help or treatment. And keep in mind, for better or worse, people tend to be less understanding and sympathetic to this kind of issue.
You have your life ahead of you. Regardless of what's fair or right or real or not, and regardless of how inevitable some sort of chronic pain or discomfort is, you owe it to yourself and the people around you to do at least a little of the work required to make yourself better. Because it sounds like you haven't.