My grandma is a 62yo woman. She's been through a lot in her life. I love her a lot, but she acts kind of weird. I don't want to sound rude, so I decided I'd explain why I think that:
1. She's usually sleeping 16-19 hours a day. Sometimes she phones us (she's living in a different part of the town) and talks to us, and calls us again later and doesn't remember talking to us before at all
2. She starts crying over the smallest problems in life
3. She was a gambling addict
4. She gets really euphoric and does really stupid things that could hurt her or us (gets in fights with the police and everyone else, talks to Top shop and similar stuff using my mother's data- name, birthday, everything; wastes a lot of money on things she doesn't need...)
5. She has also threatened to kill my cousin's father because he was a jerk
6. Overly sexual personality which I wish I didnt knew about (accidentally opened her gallery when I was 10, I don't want to talk about it)
There's more, but I don't think any of it would be important here. She often gets into fights with my mother but never changes the way she acts. 
She refuses to go to a psychologist, let alone a psychiatrist, and both me and my mother know that she needs to do it, but she just won't hear us out.
If she does have a real mental illness (which I'm almost certain she does) is it inheritable? As much as I've heard, she started acting like this when she was around 40.
My mother is 43 and she's completely normal (she had her depressed periods but she's okay now). But I'm 15 and I'm showing signs of not being really mentally stable. I've had about 10 hallucinations in the past couple of months,and I have depersonalization really often lately. (She doesn't have these problems) my dad is against me going to a neurologist/psychiatrist. 

Could anyone please answer this? What do you think is my grandma's problem and what's going to happen with me?
Thanks in advance :).