As above, not an issue normally for that kind of joint honours degree.
However, if you don't enjoy maths, why are you considering a joint honours degree in economics and anything? Economics at degree level is necessarily mathematical - it's not an essay based subject (on the whole), unlike at A-level.
I'd say just drop FM entirely, and apply directly to history degrees (and/or economic history, if that floats your boat - as that's not the same as economics and is pretty non-mathematical).