Well a couple of months ago interest rates were set to go up which is presumably why you took the fixed rate interest in the first place? To have the security of knowing the repayments. Don't see how your financial advisor was at fault?
Yes you can break the fixed term, ring your bank and ask them how much, I think it's 6 months interest, so it will be a hefty cost. But bear in mind that even though interest rates are set to go down, it doesn't mean they won't and nobody but nobody knows what way they will go.
Also don't forget that banks can themselves increase the rates without the ECB, look at the Permanent's variable rate which is 6% or thereabouts. At some stage banks are going to want to make more profits and when they think they can they will increase interest rates.
If you want to overpay, pay into a high interest bearing account now and when the 5 years are up, lob the savings into the mortgage.