You may experience weight gain. There are things you can do to modify gaining weight. When you first stop, don't be surprised if you find yourself feeling cranky, grumpy, crabby or downright angry. Withdrawal from nicotine will be physically uncomfortable and you may feel deprived and generally annoyed. It is important to talk with someone about these feelings rather than venting at someone.
Anger can hurt.
You may end up feeling guilty which could lead you to feeling justified to use nicotine again. Take a second look before you react. Withdrawal can distort one's perception of a situation. However, nicotine may have masked issues that are genuinely upsetting and anger may be a valid feeling that requires being addressed in a healthy manner. There are better companions than cigarettes.