On the other hand, if that’s a comma after “counting,” it should be a period or a semicolon, because it’s between two independent clauses with no conjunction.

No comma before ‘or’, and not one after ‘counting’ as that makes it a comma splice

you only use a comma if you’re using “or” as a conjunction between two independent clauses (set of words that express an idea [like a sentence] and can stand alone without the rest of the sentence).

if it’s just separating two objects, like “I don’t know if I like the red one or the green one,” then you don’t use a comma.

Here’s one correct way to write it:

I did not have a problem with counting; I just never knew where to begin or where to end.