How do you hold crying?

I am 28 year old and I start crying really easily, it's embarrassing and frustrating at same time. I cry when I have arguments with relatives, watching any thing emotional. Just can't hold it.
My background, I come from conservative family in a third world country. I had really difficult child hood, was bullied in school and where the place we used to live. On the top of that my mother has paranoid schizophrenia since I was 10 year old. I have seen lots domestic fight between my parents because of her health condition. And was beaten by her almost every week. And this lead me to cry in any kind of emotional crisis. My father was not alwys available, because he was working in another city. He would visit us bi-weekly, and they would always have quarrels. This thing was so stressful for me that I started getting gray hair at the age of 16.
Since past few years when I became independent, I was able to do her treatment. She has recovered really well, my parents are living together now without any issues.
But I feel weak and emotionally helpless in situations. I have become physically obese and emotionally not strong. Going through therapy also since one year but it is not helping with crying issue.
Thank you in advance
Edit: Some words
Edit1: You all are really wonderfull people, made me teary eyes. I will read all the responses. Will continue therapy, I do meditation now and then but will try to make habit. Gym also I have started since last year, but becuse of corona haven't done anything physical since past few months.


Source.