Final uni project presentation and long history of stammer. Should I tell?

I've been stammering since primary school, it was left untreated... I was never even taken to see anyone about it. Assemblies in school were a horrifying experience, so were oral exams for languages. With time I just avoided any situation I could, which could trigger it... since starting university I haven't publicly suffered with it, and I kind of was hoping I grew out of it... no-one at uni has heard me stammer, I appear quite confident, and I did get rid of it to some extent in my everyday life. Now only happens when I'm really nervous, which is usually in arguments with my mum.
But... I've got my presentation coming up in two months' time. You may think, it's weeks yet, but it's been in my mind for two years. yeah. Spoke to my personal tutor about it, and the uni counselling service who have suggested cbt but that's yet to come. I'm now also on beta blockers for anxiety...
There will be three people in the presentation - head of department, my project supervisor and an additional unknown person. I was thinking, should I maybe email the head of department about my problem? or is it better to fake it till you make it, like if I admit to it now, will I in a sense be setting myself the ground for it to happen?