Just stop doing it

First step: declutter. Look around. You spend your life hoarding things you really don't need. They take up room, they demand to be looked after. They own you, not vice versa.
Next step: If you need something, just wait for a week to see, if you can do without it.
Third step: do it for yourself instead of buying. Or find alternatives. A minimalist movement is getting more popular.  

Think about that you are a shopper because big companies play puppeting with you.