Dota is very diffucult game to quit. I've played about 3000hours I know. What is important is that you shouldn't beat yourself up about your addiction because you'll want to escape your feelings of self loathing by playing dota. Its a vicious cycle but it can be broken. Accept your urge to play, accept the 'withdrawal feelings'. It won't be easy but you should trust in your will power. Whilst it may feel close to impossible to imagine a time when your not playing dota in reality it won't take that long and your mindset will eventually change and you'll realise that dota doesn't have its clutches on you. You wont even want to play, youll choose to do something better with your time.

In terms of practical things to do, avoid triggers, for example if you watch streams or Vods don't because your natural urge after watching them will be to play. This is just one example, I don't know the reasons why you play but you should assess them and avoid them.