Hating yourself is not helpful, when it comes to relapses. It's better to accept it and try to learn from it.
You want to quit smoking, you did and now you have a relapse. Best thing to do, is analyze what chain of events led to relapse. You probably had an urge to smoke due stress? What did you do then? How did you try to fight the urge? Have you earlier have better success fighting the urge with other methods? What else could you do, when you will have an urge next time? Where did you get the cigs? Did you have them or did you have to buy? How could you stop the chain of events that led to smoking? At which point did you recognize things were leading to that direction in the first place? Could you learn to recognize the chain earlier and stop it then, when it is still easier and you are not yet having a cig on your hand and about to light it?
If you want to go really hard core on yourself, write answers to all those (and other things relevant in analysing your relapse) to paper for yourself. Do it every time you end up lighting a cig. at least you will end up with enough data to learn a lot of your self and what makes you choose unhealthy options. Very possible you will end up deciding that lighting that cig is not worth the task of writing about it, that waits for you, if you light it. Forget that nonsense of hating yourself, but do accept that making stupid choices (like lighting that cig after you have already decided that enough is enough) come with price to pay.
With all your faults (whatever they may be) you are still a lovely human being and certainly worth more than poisoning yourself with cigs.