Am I capable of doing PhD based on my advisor's words?
Though I can't relate to your situation, I have friends who were in a similar situation during their Ph.D. They were mentally abused and constantly demeaned by their advisors. Though this behaviour is predominant in South Asian universities. But it's quite prevalent in many western universities too. However, all my friends who went through such hard times, they did one common thing, they persevered.
They did not lose hope and did whatever was necessary to get the degree. After they graduated, they went their own way and are leading happy lives years after graduating.
What I trying to say is, you know that you are hard-working and a good student. What you are going through is because of your circumstances. You have worked hard for the past 4.5 years on your Ph.D., don't lose hope now. Do what's required for being eligible to defend and then change your circumstances.

All these let me to realize that I actually not capable enough
mentally and emotionally to be successful in PhD or even in any job
from now on.

Don't focus on something that hasn't happened yet. Your job now is to complete your degree. Don't worry about the success and job at the moment. Those will come. You are capable, that's why you are in a grad school.