Just a few idea which might help prove residency for the entire time:
Did you do your two degrees at British universities while you were living in the UK? They will have proof of address listed, surely.
Did you get married in the UK or in your home country?
I would say ANYTHING with your name and address would count, if they accept bills - including tax credits and council tax letters.
Are you registered to vote for local and European elections, as is your right if you are a EU citizen?
I don't know much about UK taxes, but aren't you mentioned on your husband's tax form as a dependent, if you don't work?
We did citizenship the 'other way round' last year - I'm a British citizen who took on citizenship of another EU country. It was made a lot easier because our country has central registration of addresses and you get a piece of paper as official confirmation of where you live (obligatory for all foreigners too). Even so, we had to produce just about every piece of paper known to mankind, including our water bills at one point (apparently to prove that our income was sufficient to pay our utilities!). I just basically gathered every single piece of paper I could find about anything - I would do the same in your position, it's up to them to determine if it's relevant.
Are you supposed to just send everything off by post when you make an application, or do you make an appointment with someone in an office? Here in Germany we made an appointment and the woman told us: you need this, this, this, not that, etc., which really helped.
This lawyer seems to specialise in citizenship law for EU citizens, maybe give them a call.