The Beatles’ classic ‘Yesterday’ says it in the opening lines: yesterday was trouble-free; today, troubles are here and do not appear to want to leave. If you were perfect yesterday but suddenly became disabled, it will be tough for you to adapt and cope with the disability. It will be reasonable for you to grieve and even get depressed over the new reality for you and your life. But it will not be healthy if you stay in that state forever.
Accept the change. Accept that something happened —instantly or overtime does not matter— and the state of things has been altered: you were disabled (in specific ways). Since grieving over it, ruing your errors, or blaming people and events will not reverse the situation, it is best to move on and think of the past as memories.
Assess the conditions and adapt. So the situation has changed and you probably cannot do now what you used to be able to, or can do them but quite differently. Well, then, so be it. You do them if you can, and not if not. Think of yourself as merely a different person than you were before, in the same way that an obese person or foreigner is different. You are still a person, a human being, just a bit different from most.
Explore your capabilities and develop yourself. There must be things you still can do unless you are a total paraplegic vegetable. Whereas you walked to the park before, but today you have to be brought there in a wheelchair, at least you can still go there. Whereas before you played touch football with your friends and cannot now, maybe you can cheer for them or act as an informal coach.
Or you now have time to read your favorite books, do cross-stitching projects, experiment with cooking, and so on. The trick is to know what you can do in your new situation, and grow from there. Form new interests, learn new hobbies, start a new career. Use your talents in other ways.
Find new friends and live. Join with people of similar limitations for mutual support and encouragement. Often you can derive inspiration from what they did, or what you collectively can do. It is always great to be with people who understand you and with whom you can share a part of yourself as well.
Believe in your God. However you conceive of Him to be, He must have granted you life for a purpose. Understand that purpose in what you can give to your fellowman, and you will find that life is still perfect, just a little different from before.
The only disability you can have is to lose sight of yourself and what you are, for then you lose your worth, in life, to others, and yourself. If that happens, it will be most unfortunate for you, even if you are not disabled.