Your future in MFL
If you really love languages and want them to be part of your working life you need to research carefully to determine the career sectors you are attracted to. Taking self evaluation tests such as kudos which you probably already have in school can give you some ideas; bear in mind though that it is expected that most people will change their career path several times over their working life so your use of languages could evolve over the course of it.
More than one language?
To give yourself the widest range of opportunities when you are going into the working world it is best to have a diverse portfolio of skills and if you count yourself "a linguist" you should probably learn at least one other language alongside French. It is now possible to start languages from scratch at university so this is something you should consider doing; it is much easier these days to keep up languages you have learned with the easy access there is to target language media and with travel being relatively cheap.
The websites on the right contain lots of information to help you find out how other linguists are using their skills in their professional life.
Languages Work site
-this site gives examples of jobs where languages are part and parcel of your daily working life => Go