Unfortunately no one here can tell you why you are drinking more than usual.
Although it does not appear that Diabetes is hereditary in your family, it does not mean you cannot develop it.
Of course I am not saying you have the condition but I would advise you to seek advice from your doctor and get him/her to perform some tests.
There are other reasons for develping above normal thirsts.
Some are:
High blood sugar
Kidney disorder
Dehydration (of course)
Excess alcohol intake
Liver problems.
There are several other causes.
The reason you urinate more could also be a sign of diabetes but it is also quite possible that it is because you are drinking more water than normal.
My advise must be to consult your doctor and ask for the problem to be investigated.
For more information regarding thirst please visit:
Why Am I Always Thirsty?
I hope this has been of help and good luck.
Poseidon