HELP!!! Having family issues with MOM?

Im 18 and a female

Over the recent years my relationship with my mother has been on edge. she has depression on and off and our money situation has not been that good.

She has often borrowed money from me, tell me she would give it back soon..waited for a year. and still does. it would have bothered me if she had asked but sometimes she didnt.

Also... I had a puppy for about 1 month and she decided to give it away without telling me until the day of. later our family got a cat.. and i told her"Dont give her up,, and at least tell me" well guess what.. she didnt.. visited my grandma's place and the cat was gone. so now I have trust issues with her.

I find that she is also bad with money buying house stuff when she knows we dont have alot. then when one of her automatic bills come out she turns to me for help.

yesterday i came down with a sore throat etc. and told her i need to go to the doctors. she said she would like to visit macy's for about 10 minutes, should have known better but i said yes. we ended up staying 45 shopping and another 30 at the cash register. I was buying a bath mat and she said wanted me to get up to 25 for 10$ off. i didnt want to and then she said "im her mom and where buying it"... I'm 18 you have no control what i buy with my money!!!! than she tool the three towles I BOUGHT and only gave me $3. saying this is the extra over what you would have spent. she took three towels at $2.79 each.

sorry it's long