Most insecure, needy and desperate people operate almost solely on emotion alone. Not only do emotions obscure their sound judgment, but emotions by their very fluctuating nature also make it hard to stick to any particular course of action.
The worst thing you can do to your chances of getting your ex back is be seen as not sure, or don’t know what you are doing to make the relationship work.
To show that you know what you are doing, don’t try to do too much too soon. This is especially important when dealing with an ex who is not very responsive.
Small consistent actions get you further than big drastic emotion-driven decisions — like cutting off all contact and two weeks later coming back claiming you want to give the relationship another chance. It doesn’t inspire the kind of trust that communicates confidence in what you are doing.