There are apps that can automatically track in- and outgoing payments for your account, as well as classify them to give you an overview. I use Finanzguru, though I suspect that’s only available in Germany.

If you’re struggling with money, here’s my approach: If it isn’t absolutely necessary to have, sleep on it at least once before buying it, no matter how cheap it is. Works quite well, its weird how much your perspective can often change within a day.