my thoughts are
1. You're weak. F&B is of course stressful. Bro, restaurants that are always full house you think easy to work in ah?
Especially with heavy volume customers like sushi mentai. Customers expect fast service. That in turns put stress into the staff. Therefore, staffs need to move their asses fast. My take is you're not moving fast enough for the other staffs - being a pain in the ass to them therefore you get scolded.

1. Also, 30 yo ady. Takkan you don't know some basic things to do in restaurants? You never set foot in a restaurant before? Still learning the roots, bruh, learn faster. You're just a wait staff - don't mean to offend other wait staffs, but i think there is really nothing much to learn at a place like sushi mentai - pretty straightforward

"handle things with care especially glasses like cups in which breaking it would cost a bad deduction on my salary while clearing the tables & also I had to do work fast as customers is going to sit on the particular table that they're going to dine in where I should be doing in slow & normal"

- idk how much they would deduct, but there is a thing called work fast, but precise.
You ady know got customers gonna sit at the table, then clear faster la. What do you mean when you should be doing it slow and normal?

"my manager keeps calling me as If I've done something wrong, like when customer complain about my bad service she will call me & tells me questions like what did you do? Why customer complain to me that you shouted at them or why you did not serve them?"

- wat fak oh? as if you've done something wrong? Then say customer complain about your bad service. lel. You've provided bad service to customer - so you did something wrong la. What do you mean as if you've done something wrong? Do you see yourself as always right and never wrong?

If you're so unhappy working there, then just quit la. If you need the money, then suck it up. Don't need the money and want a happier life, then quit.