Is a TEFL course worth it for a Zimbabwean passport holder?

Greetings I hold a Bachelor's degree from Monash University Australia and I have been contemplating on a doing a TEFL course. I just want to find out what is the real success rate for an African non native english speaker to land an ESL/TEFL job. Is it worth doing the course? . My second question will I am completing my pgce and soon I will be a licensed teacher. When I become licensed teacher will I still struggle to land a job as a non native english speaker to teach subjects like mathematics,english;science;geography and business studies related subjects like economics and accounting.
Thank you for your help.