What got me going was setting a specific goal for myself to abstain from something for a set time period (in the case of nofap, three weeks) and then keeping that momentum going by breaking a new personal record every day (I've gone 4/5/6 weeks without nutting, might as well keep going). Now at over a year + one month of nofap and I don't think I could ever bring myself to whack it again, the shame would be too much to overcome.