I wanted to ask if the mortgage interest on 45k is benefiting you from a tax deduction standpoint. Also echoing what was previously said about leaving enough money in savings for an emergency. You will still own the house as you stated for a few years, what might need repair or replacement? Is your mortgage rate is greater than the interest earnings on your savings? Is the money used to payoff the mortgage coming from a investment vehicle that involves selling shares or paying a transaction fee? Do you have the discipline to continue making deposits into your savings account equivalent to the mortgage payment to shore up your depleted balance?
If the money is sitting in a savings or money market account earning next to nothing in interest perhaps making a lump sum payment to principle might be a option. You could ease any anxiety about depleting your cash and still earn the equivalent yield tied to your mortgage.
At the end of the day if this causes you any amount of unneeded stress you can always table this decision until you feel confident that you are putting your best foot forward in your financial affairs.
Good luck!