My tuppence worth.
I'm assuming you want to sell your place, and buy at the same time?
Currently, banks aren't doing bridging loans for house movers. If you want to be able to buy & sell at the same time, you will need to be in a chain - I.e. you buy subject to sale of your house. The proceeds of your sale clear remaining mortgage, with balance paid to your solicitor, which would probably use to part fund new purchase, and the balance would be your new mortgage.
None of this is straight forward at the moment, but works if you're selling in an area of high demand.
Now, when you are buying you will need to pay a booking deposit, and the balance of 10% on signing contracts. You won't have proceeds from your sale yet so you either need this cash, or get a loan.
I'd be holding back at least 10% of the amount you think you'll buy for to make that step easier.
Pay the rest off mortgage, and try get a better rate for the balance. Try for 2.75% with AIB.