stop playing with me.
When somebody is good with you one day, and the next day he breaks you down, it's like you have a good feeling one day and bad feeling the next day... stop playing with me (or) stop playing with my feelings.
"Dejar de hacer" would be used for "To stop doing" so I would go with "Deja de jugar con mis sentimientas" for "You stop playing with my feelings" I do believe you would use the ending of "a" instead of "o" in the word "sentimientas" because you are a female. If I am wrong I am sure that the gurus will weigh in soon. Hope this helps.
It would be sentimientos.
Other than that, I agree with Jason.
stop playing with me. Feel free to choose one or all of them...
Deja de estar jugando conmigo....Stop palying with me.
No juegues conmigo. Dont paly with me.
No te burles de mi.........Dont make fun of me.
Deja de estar jugando conmigo..........Stop playing with me.......
Deja de jugar con mis sentimientos......stop playing with my feelings.....
No te burles de mis sentimientos.......dont make fun of my feelings.