To be successful on Upwork, you need to be professional.
i. Get a portfolio of the niche you are interested in.
ii. Write a 'human portfolio for each job
ii. See through your client's eyes
iv. Be determined to get the job and be excellent and extraordinary
v. Negotiate a good fee, this will also encourage you to put in your best.
If you have a great profile that looks professional or capable, your nationality does not matter.
3 proposals is nothing to what you should be doing. You cn do better. Due to the new membership rules on Upwork, I'd advice you upgrade to the plus plan so you can get enough connects to apply for jobs.
Also try to review your proposal writing skills. Kindly check through this thread to get some tips.