The pressure to quit an addiction such as tobacco, alcohol or drugs, is always there. It is a struggle with the self. The self is unable to bear either of the two states of mind.
The most important thing is to leave the struggle. Know that your mind will lead you astray. The mind (a nerve center of high degree, but imperfect in true knowledge) will constantly hold the opposite before you. Why? Because the mind is a slave to the physical addiction.
Step one is to leave the struggle. Get outside of the urge to renew the addiction and the external pressure to stop.
Step two is to view your struggle from another vantage point. To be more objective, picture yourself with the struggle. See your-self as a victim of a hopeless round of a physical and mental process.
Picture the pain, fear and agony. The need the hopeless desire for fulfillment, where no fulfillment can be achieved.
Step three is to commit yourself to freedom by being objective, and holding the desire for the substance you have abused, and seeing that the substance is abusing you, you want to free yourself. Find a daily routine that will fill your time, work, exercise, pray of meditate, work on a hobby, but keep busy. Keep the mind occupied. Keep the mind from seeing itself in control. Your will power is in control, and you can subdue the mind. Avoid association with former places and people who will view you as you were.
Work for freedom, however long it takes. Stay on the path you have chosen and it will become enjoyable as you continue to be occupied for the entire day, and sleep well at night. Slowly you will slid yourself out of the mind enslaving routine of addiction. slowly you will become your own friend and can reclaim your life.
Nothing worth achieving is easy. Your goal is for your own freedom and a real future.