Lost old passport and Visa

HELLO,
I just wan to ask a question as I've lost my old passport and my old visa, I am applying for a naturalisation but my current passport and visa doesn't cover 5 years that i've stayed in the U.K.

I don't really know what to do.
I have other documents like certification from college can I use that to prove that I am present in the U.K for more than 5 years?

Thanks.

What "visa" exactly do you currently hold??