Haven't you posted this before?
If she said she has no feelings for you, leave her alone. It does not matter how long you have been together or how much you love her, it depends on both people.
Not many like to cast spells for others. Also, if someone else casts a spell for you, how do you know it will even work? It will most likely not work if someone else casts it for you.
Magic cannot help you here, I am afraid. And if you do try to use magic to get her back, well, that is taking her by her own will which is not right at all.