I am confident in myself and confident about my abilities. I am comfortable with using those terms. But I don’t think either is wrong. I have heard it said this way more times by people I respect and so this is more natural for me to emulate.

Colloquially we say "confident about (the future/an outcome)" and "confident in ourselves/our abilities" it's that simple to remember. Although grammatically you can use any form you want. Examples: "I am confident in my ability to succeed" "I am confident in my desire to succeed" "I am confident in your ability to understand this" "I am confident in being able to complete the task" "I am confident they will win the championships this season" "I am confident about what the future holds for me" "I am confident about my choice of tiles to complete this kitchen project" "I am confident about the success of this venture" You can change the "in' and the "about" in all of these examples if you want. It will only change the received perception of how 50% of the people understand your sentence and exactly what you mean. English is like this. You will get used to it. You can also insert "confident of into the sentence if you want"

The difference comes down to the difference between the prepositions "in" and "about". "In" expresses interiority, being inside. "About" expresses proximity or relatedness. Normally, you would express confidence "about" something or someone. Confidence "in" is something deeper, like believing in someone.

They have slightly different meanings, but ith be used. So, 'about ourselves' talks more about abilities. 'In ourselves' is more personal and deeper....it is more about being confident on who we ARE!

In natural English, we would say both "confident in our own abilities" or "confident about our abilities". You could say "confident in ourselves" but that whole sentence is not natural. On the contrary, it would be better to say, "What is the most important is that we continue to make our best effort" or something like that.