Keep trying, no one trusts Nigerians but we still push. All I can say is keep pushing bro... You'll land something soon. That was how I started and I'm still struggling...
Congrats on getting your first job, you also got a great review so hopefully, that helps in getting more opportunities.
I do have a suggestion. It might be best to pick two of the many skills you listed and focus on those. Create specialized profiles for those two and focus on getting jobs in those categories. Clients may have more confidence in your ability when they know you're focused and can deliver the best in the category they're hiring for.
Right now you've listed:
This probably has the opposite effect you're hoping for. Clients want freelancers who are the best at what they need, not the ability to do many things relatively well.
Hope this helps!
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.