If I may, I'd recommend first try to understand why you can't take a decision, is being afraid of making a mistake for example or is there something else? Then, you can start practicing with mundane decisions like picking a different flavor of ice cream instead of your usual one, try to identify decision like that example that have no consequences and don't overthink it, just decide. The only way to change this is to retrain yourself to break the association.

If you can, do some therapy, it will help.

Good luck!