Droopy side of face, getting worse!

I've had the right side of my face be a little droopy most my life. But only slightly! When I first noticed it on a passport style photograph it was because my eye looked a different shape and looked like it had a slight cast in it, like it wasn't looking the same way as the other one. I looked back at photos of me as a child and realised this was there then too!
My eyesight has always been weaker in this eye too. And once when I was about 12 I had a virus and this eye swelled and I couldn't open it. But the other eye was fine!
Well.... in recent years I've noticed that my eyesight has got worse, my eye has become droopier and now.... I can see that the right side of my mouth looks droopy to compared to the other side! Its clearly a problem with the one side of my face and its very depressing as its getting worse at what feels like a quick pace!

Any advice on this? Please help! :(