chossing the optioal

Hallo sir ;

I hope to get your advise on my current situation .

I now have to chose between two optional papers , and I already decided to take P7 , as I work as an auditor , so hopefully it won’t be a difficult subject to me .

my issue is choosing the other one:

I had already decided before the result to take P5 as I found the subject is really interesting and I enjoyed studying f5 and p3 , but unfortunately I wasn’t lucky in passing P3 in my 1st attempt and I now have to retake it again in June , so I am very afraid now to take P5 and fail , ( you know it is in line with p3 , and I don’t want to put my chance to be affiliated by June 2015 into risk ).
maybe I am not that good in writing essays !!!
I decided to take P6 instead , it’s huge paper but more safe than p4 as it’s 80% required computation , and I am good at that , I like tax , not bad at all , amusing , but I feel that I am not doing sth really will benefit me or add to my knowledge you know tax is changing constantly , and very specific to the country it’s applied in , but I will play it safe by doing so

I hope anyone can advice me coz I feel completely lost and don’t know what to do .

thanks a lot