Hi Everyone, Sorry for the length but I am super stressed about the well-being of my friend and feel so helpless as to what to do and if I can or should do anything for her.

I will start with a little background. I will call her Sunny because she is a literal ray of sunshine. 

We have been friends for about 8 years. She came into my life asking for help... I know... I just want to be clear I am not a person who goes around looking for other peoples battles to glob onto or save anyone. Sunny really chose me as her friend and I would even say we have a spiritual connection. Our relationship is unique in my life. Other people in my life besides my husband would think our friendship seems strange because we have such different lifestyles.   
Here goes...we lived in the same neighbourhood and she needed out of an ex's house, I let her stay with me for a time. She approached me one morning when I was in my front yard and I could not say no to this lovely person. It was messy.. I didn't know anything about her and she was coming off of strong psychiatric drugs and in the days following her moving in she became non-verbal/really sweaty and was in a kind of happy lala-land. I took care of her and then looked through her stuff because I was so freaked out and found a prescription... can't remember what it was called but my friend who has taken them told me coming off of them is a big ordeal. She eventually moved out with a guy. At some point after this she started going from weed, drinking and occasionally crack or cocaine use to over the years moving more towards crack. I partied in my early 20s so I never judged her and to be clear, we never did any hard drugs together except one time we had a night out drinking and did a few lines together.

Her diagnosis is manic depressive/bi-polar disorder in Canada

That was almost 8 years ago. Since then Sunny and I haven't always talked.. she has sort of bounced around relationships and cities in our home province of B.C. or Alberta. We always stayed in touch. She usually reached out when she was back in the psych ward. She would often end up there after drug (crack or cocaine/alcohol) binges. I have never met anyone quite like Sunny. She isn't the pop-culture image of a user (I know that people often aren't). I have always found her trustworthy, very caring, easy/fun to be with. She has an almost innocent quality about her. It can be to her detriment because she has been naive to bad people who have taken advantage of her kindness and the support money she gets for her illness. She has also dated some legitly sane nice men. Which brings me to my next points...

Sunny has mental health issues. She had a neglectful Mom and she shared with me that she knows her father sexually abused her and that is has never been addressed. She talks poorly of her mom and I am aware I get just her side but I know Sunny and she is hard pressed to throw anyone under the bus. She is honestly an agreeable person who dislikes conflict.  
I have never throughout the years I have known her heard her speak unnecessary ill of someone. Her mom had her brought into a psych ward in her teens. It fucked her up bad and she hasn't gotten out of the system. 

I also know she gets confused about who is on her side... probably from being abused when she was young and the way nurses can treat them. She told me once when they took her cold turkey off of an antidepressants and she had paranoid delusions about me. But she could self-reflect on that soo...?   
Idk.. but I know that a week ago she was at the tale end of her injections. She was getting passes everyday to hang out with me and sometimes my man depending on the time of day. We were doing normal stuff.. walks, cooking, she had to get a phone, playing with my 8 month old. She was somewhat anxious and forgetful but functioning and motivated to get her life together. She was keeping a journal, getting up and taking care of herself/hygiene, keeping her personal space clean, keeping in touch with friends.   
The day came around for the monthly injection... the nurse said she could refuse it. The doctor didn't like that and she got the injection. The next day we picked her and she was a totally different person. No energy, depressive, unsure of herself. SHE HAS ALWAYS SAID ONE OF THE REASONS SHE USES AMPHETAMINES IS BECAUSE HER DRUGS TAKE ALL HER ENERGY. I can say that they do indeed do that she turns into a fucking vegetable. This is not the first time I have witnessed the change after an injection.

I talked to her today and she seemed totally off the rails. At first she spoke in a young girl voice about doing art then she said "I dunno I have nothing, I am a lifer.. they put me back on lithium." She was all over the place, it scared me.   
She said she wanted to be there then started crying saying she hates her life and wants to leave but she can't.   
She said she has dementia... she gets this injection and she literally forgets how she got on the phone. I can see over the course of knowing her the drugs make her sedated and more agreeable to being institutionalized. They also have caused her to develop physical twitches and lose confidence in herself. She used to walk with confidence and speak assertively and recently she has been showing a lack of confidence in simple choices like what phone to get or how to react to people we see at the dog park or in the grocery store. It seems like she in becoming institutionalized.

I am on here asking anyone who has experience dealing with a family member or friend in this situation or has gotten out of the system themselves. How much can/should I advocate for her and how do I even begin that process if it is appropriate? I am not a family member. I could try and connect with her mom but it might go very poorly. Any advice/ hard facts/ truth/ suggestions are greatly appreciated especially from Canadians because I know mental health varies from counry to country.

Thank you for reading this super long post!