If you have a fear of quitting heroin because you are afraid of the heroin withdrawl symptoms then continue reading I will put some of the myth of heroin withdraw to rest.
Now if you plan on stopping heroin at home then yes the heroin withdrawl will be somewhat difficult. There are several withdrawl symptoms you will have to deal with if you decide to stop using this way without any medications to help ease the pain of the heroine withdrawl.

Heroin withdraw symptoms
Loss of appetite
Insomnia
Vomiting
Diarrhea
Headache
Goose bumps
Chills or sweats
Wanting to give up and go to the dope house
Heroin cravings
If you think you can cope with all of these symptoms then by all means go for it. I have went through heroin withdrawl this way and it was no picnic but it can be done. My suggestion to you is that if you are serious about quitting in this manner is that you should invite someone to come and stay with you they could be the difference whether you make it or give up and goes use before you are half way through with your heroin withdrawl.
The best way to go through heroin withdral is in treatment. There you can go through heroin detox rather comfortably. Do not be afraid because a medical staff will administer medications to help ease the withdrawl. One can go to rehab and go through the whole detox process in about 3 or 4 days depending on how much dope you were actually using.
However when you are finished with your heroin withdrawl detox I would recommend that you continue your recovery in residential treatment. This will help to prepare you for when you leave residential treatment and go home. I have kicked heroin both of these ways so trust me you can get clean with both. The idea though is to remain clean!