There are way more years behind me than in front of me. It is depressing & frightening. There are so many things I can't do anymore 'cause my body has lost interest or is simply unable to bend or twist or jump like it once did. (Once again get your minds out of the gutter. I still have enough flexibility for that. I can give you references if you want.) I have a whole multitude of regrets. Regret is the biggest waste of energy known to mankind. Its done. You can't fix it. Move on. Move forward 'cause you're not dead yet. As long as there is breath in your body you have something to contribute to the world. Yes you do. Even comatose patients have something to contribute. Keeping vigil has a way of uniting people while stripping away all the unimportant nonsense we weigh ourselves down with. Think about all the people employed by a comatose person. Doctors, nurses, aides, pharmaceutical industry (which employs thousands) in addition to housekeeping services. Its astonishing just how many people are there for those who can't do for themselves. A comatose patient not only employs these people but also gives their lives purpose & meaning. And these employees bring home all that they've gotten on the job. Then their families turn around & spread the goodness to their friends & coworkers & classmates.
Your life does have value & meaning. If you need more than that find a way to contribute in another way. Hospitals are always looking for volunteers. Volunteering at the hospital gave me the confidence to go get a paying job. Without little old ladies who needed help in the bathroom and the old men doubled over with the weight of a lifetime who needed doors held or help with their coats or prescriptions I would never had any confidence in myself at all.
The Dali Llama once said "Those who think that they are too small to be significant have never spent the night with a mosquito in the room."