What is the treatment of depression, back pain, and arthritis?

Hi doctor,

My mom has been sick for a while now. My mom is around 45 and not at a stage I like seeing her in. Strangely, she has periods of happiness and wealth and other periods of complete depression and delusion. I know she has had back pains and arthritis for a long time, and she takes several drugs to relieve the pain. The thing is that she takes so many drugs that it may be another illness. So, I am unaware of her condition, if anything more than arthritis. Why would she have these crazy mood swings if she just had arthritis? What she does is pretty insane. Sometimes, she will be a great mother. She will have fun with me, talk to me, and watch movies with me, and I love being in her presence. But most of the time, that is not the case. My mom does not leave the house like ever. She does not have a job and sits in bed watching television. She has these periods of complete insanity. She will be wholly dazed and seem drunk. I sometimes have the feeling she is mixing alcohol with her medications. She will start saying things that make no sense. She curses and says stuff about dying or her pain. She can barely move. Sometimes, she just lays on the floor, acting completely drunk and insane. She yells and curses at my dad for things he has never done. She does it without caring if I or my little sister is there. She turns into a completely different person. She is weak and gaining weight. It honestly scares me to see her like this. I hate not knowing what is wrong with her and assuming she has bipolar disorder. Some say she started getting pain and arthritis in her joints after my sister, brother, and I were born. I feel incredibly guilty. Some people say it is menopause. I do not even know what that is. I want to see what is wrong with my mom so she does not seem like some weak, sick, tired, awful mom to my little sister. She has been like this for a few years. I forgot to add she also has big trouble breathing. I try to help her, but she is weak and can barely stand. She wobbles a lot. It is unfortunate and frightening. Please help.

Thanks.