She is always thinking about me and wishing me to break up. Can this be the reaason that my current lationship is so bumpy??
No. Incompatibilities, and lack of knowledge about relationships is usually the cause. You can change your own relationship, your ex cannot. And having talked to some Wiccan friends, spells are NOT to be used for selfish reasons, ever. If you believe that stuff. So, forcing someone to break up with their gf and fall in love with you is bad bad bad.
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
(Please note, we give the best advice we can based on the information given in a post. For better advice, please include the age of all romantic partners.)