What you're reporting makes sense- severe stress can make you ill both physically and psychologically.
This is a hostile working environment that you're leaving and taking care of your health is the most important thing.
Even if this job/individual had corroded your self worth, try to remember that you are not defined through a job, a title, or another person's opinion of you.
You were stuck in the role of a victim at work and now you can start to see yourself as a survivor and over time as you find something to do that you love, as a thriver.
Unfortunately, even adults can bully others. And, for the same reason- to deflect attention from themselves. Another adult/boss can bully an employee as an unhealthy way to assert their authority, because they're authoritarian or tyrannical in their approach, and possible because they lack other managerial/people's skills.
After your last day at the job, you may want think about connecting with a counselor to help you through this. If you're not on any medications, it would be something else to discuss with your GP. You may also want to find out if you could qualify for unemployment by speaking to someone at your local Dept. of Labor.
No job or another person should have the control to ruin your life and health. You've taken the most important step now, to leave the job. The rest of the steps you take would help you move on one step at a time. As Confucius has been credited of saying "Our greatest glory is not in never falling but in rising each time after we fall."
Yes, it is normal to doubt yourself because changes can be anxiety provoking. Changes however can lead to freedom and growth. A change of pace and looking for more positive energy in your life is better than staying stuck in a job because of fear. You have most likely had other jobs before this one, and you will have other ones after it.
You were a targeted individual at your job and a job is a place you go to work and earn a living not be abused and traumatized.
Work on your guilt. You did not cause this situation to yourself. You however want to end this suffering and get out and move on with your life. Your doubt stems from not knowing what is next for you. It's natural to feel concerned as long as you do not allow for the doubt to consume you.
Depending on what you want to do, there are some online jobs (or you can have two part time ones. Some companies pay benefits to PT employees) Check out virtualvocations.com and ratracerebellion.com