What do you do if your spell goes wrong?
Damage control! Try a reversal spell, but probably most of the damage will have already occurred. Releasing a spell is like unlocking a floodgate. You wait until the water recedes or dries and then rebuild. That is why magick should be taken seriously, and you need to ponder every spell and its reasoning.
Was your spell meant to be cast? Is it for the good of all, or are you trying to manipulate energy for your own gains without considering the consequences to others? Did you consider your words and how they could impact the spell? Words are magick and have a lot of power, and if you weren't very specific about what you wanted to achieve, or if the wording of your chants or prayers had more than one meaning, you can be sure that the outcome you didn't want to happen WILL happen.
Is it possible that you blabbed to other witches about your spell, and they are inadvertently blocking the magick? Or even actively hexing? Remember, it's always best to keep your spells to yourself. Silence is golden in witchcraft.
Ultimately, all you can do is pick yourself up, dust yourself off and carry on! Next time be more careful.