I'm happily most of the time married to a man 19 years my senior. I'm 34, he's 53, and we've been together 7 years.
He's lovely, kind and in short the man for me - can't imagine "clicking" with any one else like I have done with him. Even though the grey hairs and middle aged spread have piled on in the time we met, and I am more South Park and him more Dad's Army in sense of humour - we are happy!
I think though there is a big difference between meeting in your late twenties (me) and in your late teens.
At age 19, I was a baby! In between age 19 and 26 (when I met my husband), I got a degree, travelled the world, established a career, lived independently, had relationships (nothing major, but still) and moved to another country (which is where we happened to meet).
I wouldn't tie yourself down to anyone - let alone a much older man - at just 19.
An older man dating a 19 year old seems weird to me - the life experiences each side has with those variant ages must be poles apart.
Then again, he might be "The One"! What do I know?
Tell us more about your relationship in general.