Please tell me its not just me

Does it even help to cry anymore, does it help when we act strong and cry all alone, why do we get so hurt, it doesnt help at all that they never really see or hear us. Is it fair that one day they love you and then next day they take it all back and you cant even understand how it happened and why. Why do they have to lie,cheat,verbally,physically abuse us and then blame us. Why is that all we do is love and get no support when we try and protect them , they hate us. I cant get through to her, I cant seem to understand her and she will never understand Im here to protect and love her.

From Confessing her undying love for me to silence all in 3 weeks,

These are her changes :

The 1^st Week,

Not sleeping
Not Concentrating
Not eating
Exercising A lot
Creative
Impulsive
Mixing up words in her sentence and speaking to fast and not making sense.
Over promising and declaring emotions and feelings 
Spending Money Extravagantly


2^nd Week,

Didn't go to work for 2days.

Hostile
Verbally and Physical Abusive
Selfish
UN reliable
Unable to Reason nor see things rationally.
Destructive
Cheating Lying


3^rd Week,

Distant / Doesn't Communicate
Doesnt want to see me
Selfish
Hostile
Irratic
Verbally and Physically Abusive
Unable to Reason nor see things rationally.
Makes contact , asks to see me and then 5min cancels.

Her personal appearance has changed; her voice / look in her eyes , and I have no idea who she is now compared to what she was like in week 1 from been loving and kind
to been the complete opposite, swearing, shouting, hitting, screaming , performing the works, She becomes like a child when she cant get her own way
if that way is hurtful to others and herself even if it would cause more complications. She can't reason and then blames me and tells me im messed up.

All I do is care for her, she just carrys on with no remorse and tells me to forget and move on. Her actions, her words nothing ties up.

From my side, I find it out hard to understand and I honestly can't cope with her anymore, as much as it hurts me to write but I cant. Worse now is that it hurts cause I didnt even do anything, and now im the one thats left hurting, no doubt she is having "fun" pushing limits to make her feel better with no emotions to anyone but  herself.

please help me, i need to know how to move on cause each time she comes back , she breaks me and i take a long time to deal with things and try and be ok ,
I feel like a sick game, when im healthy in mind,soul and body she wants me back and then distroys me.