Learning A Levels Independently

I recently got my A Level results back and I was very disappointed. Needless to say I want to resit but one of my A Levels (Statistics) can’t be retaken and I don’t want to do it again anyway. Instead, I was thinking of learning A Level Economics in a year independently. Is it possible to do this?
If I was online courses such as Uplearn could I still come out with a good grade?

So for 2020, which exams/subjects will you be sitting?

A Level Business Studies, Accounting, Economics and Statistics.
I’m not definite on Statistics but if it’s possible I may do that as well.
Economics is the only I haven’t done before.
I was contemplating maths but it looked too hard.

To be honest, it depends on a lot of factors (as it always does).

What were you grades for your other subjects?

Do you find exams particularly difficult?

What are you intending to do at uni or wherever you go?

Which unis will you be applying to?

How was the workload for 2018-2019?

Ok so,
I got a BCD
I wouldn’t say the exams were particulary difficult. My timing was awful as I ran out of time on most exams.
I’ve been intent on doing Economics or Politics&Economics at Uni

I got a place at Aston uni to do a foundation year in business which if a excelled in, I could then do an Economics degree. However I’ve only really been interested in Uni of Birmingham and Loughborough.

The workload was medium to high. I could’ve done better though.
I was just wondering whether Econ is doable in a year independently