It must be something of a relief that there's nothing that a period of reasonable rest shouldn't put right. Do be careful of the 'knackered' bit, as you may be more tired than you even realise, & so need to be Very Kind to yourself for quite a while!

If it's vocal/throat strain... have you tried experimenting with different speaking pitches, for the times you really must talk? I've found taking my voice downwards and speaking gently in chest voice can be a useful temporary measure when I have throat trouble (as long as I keep the sound soft, with no forcing at all).