I stopped smoking for a 3 month using nicotine gum but yesterday i couldn't handle it anymore , i bought a packet yesterday and i smoked, ?

You relapsed: Which is part of any addiction treatment, whether tobacco, alcohol or heroin. Most people relapse at least once, and many relapse many, many times. Don't beat yourself up - it's called "abstinence violation syndrome." go back to the gum, or better consider use of skin patches, and get into a support system as well- having a program doubles the chance of your success. Consider Chantix as well.