Hello Oyioche1,
Thanks for visiting this thread.
1. I don't have the full information about your application, so I cannot make any judgement call about your chances of success. Furthermore, regardless of how well your application is put together, no one can tell you whether it will be successful or not, you just need to try your best.
2. I disagree with
@Simba112 whos says that going for a graduate diploma after a first degree does not show career progression. Career progression is a function of your current job experience or your bachelors degree or both. For example, if you have a first degree in Microbiology, but working in a Bank for the past 3-4 years, you can apply for a post graduate diploma in Business Management. The post-graduate diploma is above your first degree, and it is also related to your most recent work experience.
3. Please refer to my earlier posts on self-evaluation. If cannot evaluate yourself before putting in your application, then you will be wasting your own time. You need to understand the logic behind your application and help the VO to see it as well.
All the best.
Omofar