Hello friendafar.  Casting malicious spells, putting hexes and curses on people, etc. is using magic for malicious purposes.  Some people refer it as, "Black Magic."  I must warn you that Black Magic is notorious for its inaccuracy.  When the Back Magician misses his mark, which is almost always the case, the consequences are that the magician winds up hurting, and sometimes even killing one or more of his loved ones, or one or more of his victim's loved ones.  Additionally, I am not a Wiccan.  However, Wiccan doctrine dictates that, whatever evil the magician directs at another person, returns to him/her threefold.  My advice to you is not to try it.  I believe that it will only weaken you and exacerbate your troubles.  It is a far better idea to use magic to empower oneself.  When you get inside your head and introspect as to the reasons why you want to put hexes and curses on other people and cause them bad luck, I would wager that you would find in yourself feelings of helplessness, fear, being controlled, lack of self-confidence, low self-esteem...even jealousy, etc...  These are feelings that consume a great deal of time and energy in one's life.  They cause one to obsess, compulse, waste time and invest far too much of oneself in negativity.  They are, "weakening."  In a sense, because of your own weakness, the people you wish to hex and curse are, in effect, hexing and cursing you by causing you all of this ill will.  Rather than using magic to try to weaken them, doesn't it make much more sense to use magic to empower yourself---to rise above them so that you are no longer affected by them?  Good Luck!