As others have said, if you still have the time to, put your money in the back back in Clock Town behind the tower in the southern sector and then play the song of time to go back to the first day. There's no need to reset your game- having the time crunch and not always getting to do what you want to do is kind of the point. Going forward, try not to start any potential lengthy quests or dungeons if you're on the last day, and use the backwards song of time to slow the days down.
I suggest, as others have said, not to start lengthy tasks like dungeons and skulltula houses on the last day of the cycle. You can go back to the first day as many times as you want without consequence, so make sure to get your money in the bank and go back to day 1 so you have plenty of time to complete what you're trying to accomplish.