2D animation is going reverse

hi guys i am working in 2d game . i have created 2d animation in animation tab . it is working fine with normal speed but when i increase the key frame rate or animation speed in animation state option. it starts going in the reverse direction my animation is from let say (-100 to 0 to 100) . i have tried all the interpolation options Euler angle quaternion and Eular angle (quaternion approximation ) in animation tab but nothing fixed my issue what is possibly i m doing wrong?

thanx in advance.