Completely Stuck! Do I need to restart my city?

So I can't upgrade any of my buildings because I need more police and fire stations etc. but ive got no money? And the only way to make money is by upgrading? But I can't upgrade because I don't have enough police stations and Fire stations etc. but I've got no money? And the only way to make money is to upgrade? You see where this is going? I'm completely stuck. Yes I know I need to buy stuff to make them happy etc but I can't afford it!? Help. Is this the end for my city? Do I need to just restart the whole game?