Fear of brushing my teeth all are sensitive, it's been a year without a solid brush, have cavities now, broken teeth plus a absence on my gums, is it to late to start brushing and if i need a dentist how painful is root canal / other procedure?

You need to see a dentist immediately before abscess spreads from your condition for emergency treatment. You have too much bacteria in your system that will cause severe damage and pain. You will need to be placed on antibiotics and undergo multiple procedures if you want to save your teeth.

It's not too late to begin proper oral hygiene habits, but it will in no way help resolve your current issues. Modern dentistry is performed with local anesthesia and is painless. Seek immediate care since that abscess can spread through your bloodstream to other parts of your body.

You have, unfortunately, been dramatically negligent. As a result you describe numerous hard and soft tissue infections. GThes have already caused serious damage, and spreading through your circulatory system can cause damage to other organs. Can't fix this with oral hygiene alone, or with computer clicks, homeopathic, mouthwashes, etc. You require hands-on dental care, not avoidance. See Dentist