Being harrased and make work out of my profile

Hello all.

i joined a small trading company in Dubai as a counter sales person, where I had to sit in a counter an make bills for customer and collect the cash as my Boss told me while joining.
i started to work in August 1st 2018 on my visit visa , which was going to expire in October 5 2018.
previosly i had no any idea in Accounts on Tally ERP , after joining here I started to make Invoices and receipts and payments. Previously I have experience as a  Data entry operator.
the reason why i am posting this post is because of daily harassment i am facing from my Boss at the end of the day when it comes to mistakes which i have done in a day , some times he shouts, yells , taps hardly on table and keep pouring questions in his own way..
what I do at my work place is as follows:
1. work on Tally ERP(making bills, making receipt /payment vouchers)
2. handling walk in customers , answering their queries on product.
3. Cash collections from walk in customers or outdoor customers (supplied through company vehicle)
4. maintaining credit customers ledger
5. receiving stocks purchases
6. making purchase entry in Tally
7. Preparing cheques , payments to suppliers
8.making entry in excel file for each customer (cash /credit customer)
The main stress comes when i see that office work should be inside a cabbin is all happening in a sales counter, and multiple tasks and handling multiple people at same time, that's why I am committing mistakes regularly and i feel helpless at work place because there is nobody than me to handle the Accounts work which i have no knowledge, still my Boss questions me for pending work in tally.
   Even he called my friend through whom i came Dubai and he asked him to pay my Visa expenses to cancel my Visa, I am not afraid of getting cancelled but the harassment which is happening is very stressful.
Even i cant take my break period between 2pm to 5pm , and i am not taking my any week offs , and i ve been not paid for any extra hours and extra days(from September 2018 I am working straight duty from morning 9.45 am to night 11 or 11.30 on daily basis)

and still I have not received my Emirated ID , when I ask Boss he just keeps repeating that He'll check and let me know" (palm scanning is done on 15/12/2018)
I feel like I am getting into depression because of daily work stress and harassment.
just need some genuine advice to tackle this situation and come out of this.

my Visa is for "Sales"  from 10/10/2018 to 09/10/2020