My mother has been unhappy even before I was born, and I have been caring for her for over 18 years.

My mother is now 74 and cares for two dogs - that is the most she does for 'socializing' - taking them out. She has a history of depression and suicide attempts. I saw her almost die more than once with ingesting alcohol and antidepressants or tranquilizers. She is not and was not an alcoholic, but there were times she would do that. She had a poor upbringing, financially speaking, the youngest of many children. I know she was molested as a child, then she grew up to marry my father who was a living demon. He many times drove her to doing insane things, years of verbal and mental abuse which myself and my sister had witnessed. The issue is that my sister was/is self-absorbed and father's favorite, so she really never cared for my mother and was much of a rebel. My father would blame it all on my mother: our behavior or misbehavior, the weather, his financial problems... he was a bully in the worst way. Anyway, of course she never left him for fear of not being able to live on her own. She had very little formal education and he convinced her she was no one without him. Needless to say I hated him - but I loved her to death. She protected me from him, and even in her worst moments (suicide attempts), somehow she thought I would be better off without her.
After 35 years of marriage (I was 22), I finally managed to separate them, and I took upon myself to care for her. I had been doing so for so long, emotionally wise... always fearing something would happen. My sister is not in the picture and frankly does not like my mother. We barely spoke two words over the facebook after 16 years. Throughout the years her depression worsened and suicide attempts increased to the point of her being violent and hateful towards me. I was doing everything in my power to help her, even taking her to pentecostal churches because she was certain she was being cursed by whatever ghouls there were around. There were times she would scream and have tantrums, and blame me (the only person around her) for all her woes - either with words, looks, or actions. She hated any boyfriend I had, make rude remarks, unwelcome to him and his family. Actually I am referring more importantly to one man whom I had loved dearly - they hated each other. In the end I had to make a choice: either live with him and leave her to herself in an ALF or leave him and have her at home safe and comfortable with me. I tried the first option, but at first she was hurt and vowed never to come back home even for a visit. She would not attend a wedding nor would she acknowledge any child resulting of that relationship. After a few days she seemed better and I visited her constantly. I saw a close glimpse of the mother I once knew and loved. On the other hand he complained a lot that I would visit her almost everyday (I was on leave from work due to a reactive depression after so many years coping with her and my own problems). His hatred for her was visible and started to resent him. After three weeks I brought her home and she kindly advised me against him. She swore he was a wolf beneath lamb's skin. I gave in to her pleas and ditched him. I met someone else whom she did not seem to be much bothered by, but then again she had just recently started being treated for bipolar disorder and the meds were working fine. This man was the cause of much disgrace and hurt in my life. Funny enough she tells me that she does not have anything bad to say about him because he had never disrespected her. Yet, she still hates the first one (10 years later) whom had never mistreated and abused me. Years went by and resented her more and more. I felt I was responsible for her life while mine was on the brink. No husband, children or relatives to count on. We kept each other company, my vacations always had to include her... but what would happen when she died? Every man I met would run shortly after they knew Mother lived with me, or at least after meeting her. Last year I met a divorced father of a 9-year old girl. He had her on intermittent weekends and understood that I cared for my mother. We eventually moved in together (all three of us) and shortly after that we married. Even though they get along fine, I am always in fear she will play the same stunt. She is now careless to the point she has accidentally spilled water on a laptop and wine on the carpet. She is becoming forgetful, sometimes asks me the same thing three times within minutes, and other days she acts just fine. I work from home and she will constantly interrupt me or come knock at my bedroom at almost any time of the day, sometimes at night - for silly remarks or comments. I understand she feels lonely, and she is not the same as memory goes or even health, but I strongly feel she has alienated herself from the world and lives through me. I have a strong mix of struggling love, resentment, guilt and other things I cannot even name... And I feel unhappy, sad and angry at the same time - wrapped up in guilt.