The ruling pertaining interest money is that it should be given in charity to the poor and needy ones without the intention of reward. You did the same. Your food or income is neither haram nor there is any problem in it. However it is makrooh to open saving account unnecessarily, but it is lawful at the time of need or due to business purpose or for the intention of safety and in such cases it is allowed to open the saving account.
Allah knows Best!
Darul Uloom Deoband