A lot of people, including myself, have been negatively affected by COVID-19 this past year due to COVID-19.

Although affected is proper, a better verb to use would be "impacted".

Right after finishing my internship in 2019, it was very difficult to find a job in Jordan because very littlefew dental practices were hiring and lot of dentistsmany were shutting down their private dental practices and were havingdue to their financial challenges.

All mentionedThese factors lead me to consider pursuing my career as a dentistdental career in the USA and following in my mothers footsteps.

Additionally,But due to COVID-19, there were no flights from Jordan and, so I had to delay my Integrated National Board Dental Examination to late December, which was later than expected.

Due to COVID-19.

This sounds incomplete.

Right after finishing my internship in 2019, it was very difficult to find a job in Jordan because very littlefew dental practices were hiring and a lot of dentists were shutting down their private dental practices and were havinghad financial challenges.

All The aforementioned factors lead me to consider pursuing my career as a dentist in the USA and following in my mother's footsteps.

Due to COVID-19...

Right after finishing my internship in 2019, it was very difficult to find a job in Jordan because very littlefew dental practices were hiring, and lot of dentists were shutting down their private dental practices and were havingdue to financial challenges.

All mentionedthese factors lead me to consider pursuing my career as a dentist in the USA and following in my mothers footsteps.

Additionally, due to COVID-19, there were no flights from Jordan and, so I had to delay my Integrated National Board Dental Examination to late December, which was later than expected.

Right after finishing my internship in 2019, it was very difficult to find a job in Jordan because very littlefew dental practices were hiring and a lot of dentists were shutting down their private dental practices and [were hav] facing financial challenges.

(1) "Very little" refers to things that are not countable: "There's very little food on this plate."

(2) Omitting the "were" in brackets would make the sentence smoother.

All mentionedThese factors have lead me to consider pursuing mya career as a dentist in the USA and following in my mother's footsteps.

AdditionallyHowever[?], due to COVID-19 there were no flights from Jordan and I had to delay my Integrated National Board Dental Examination tountil late December[, which was later than expected].

Is the idea that you decided to go to the US, but there were no flights from Jordan? If so, the initial word here should be "However" rather than "Additionally". Also, is that examination required for you to get a job in the USA? Or do you need to fly to the USA to take it? Or both? The connection between this sentence and the previous ones is unclear.

If you had to delay something, then it was necessarily later than expected. Or are you saying that you had to delay it even more than you expected the first time it was delayed?