my life is worthless right now because I'm so depressed.
Your life is indeed worthless, why? Because you have decided it is so.
Magick is not the answer... Magick is like putting a plaster (band-aid) over an amputated arm... If you put enough on it will look better, but you're still going to die.
Heal the wounds first, then patch up the after effects. The only way to heal is to take time, accept what happened and love yourself. It is cliched, and there was a time people told me the same... to love myself, i laughed... And yet they are right.
Your life is only worthless because you say it is. At the end of the day we are all worthless. Do you care if i die right now while typing this? Nope. You may say you do, and you may wish it didnt happen, but you would not fly to my funeral, you would not cry, you would not care. Worthless... I am indeed. You need to find that worth inside yourself. I cannot give it to you. Nor can your ex, nor god, demons, angels, spirits... only you can work out WHY you are NOT worthless.
Why do you want your ex back if it isnt true love? Would you handcuff him/her to you all day every day even if they never spoke a word? Even if they loved another? Adored him or her and smiled and look at them every chance they got?
If you answered yes then you have some problems that only you can solve. If you answered no then you just solved one problem. Love yourself, give yourself worth and f**k everyone else! Enjoy yourself!