Killer thoughts.

Hello, sorry if I don't express myself right but it's very hard for me to put my thoughts in the right way. This is going to be very long. I am very depressed from quite a lot of years years. Going through puberty was the worst. I used to constantly self harm and not be able to get myself together. About 4 months ago I changed and stopped self harming, I also started loving myself more, although this made me more isolated than I have ever been, I have a feeling that I did everything for people around when I did it, as it was hard because of lack of motivation. I didn't eat at all for days because I considered it a waste, didn't drink water, didn't try to progress and do something positive. After getting horrible abdominal pains and constant headaches I decided that this will take me somewhere very bad. I feel like I am not as carrying towards people as I was before because of this. I can't spend any time with my mother now, in past I could. Every single time I sit at the table with my family I can't stand them even eating, the quietest chew makes me irritated. It takes a few moments before I starting daydreaming about stabbing them with a fork, I get very graphic images in my head of me killing them in different ways. I feel disgusted , worried, but somewhat careless at the same time. I'd keep looking at knifes while their back would be turned to me, then at them, then again at knifes. We didn't argue from a very long time, with no absolute triggers I get these urges. They could be telling me about their day or a joke it wouldn't matter because my mind would only think of killing. I am worried that if we would get in an argument it would be very severe. In the past I never felt like this, it started developing in my mind only since I stopped self harming, and since I am feeling less unhappy. I feel guilty that I start loving myself now, but the way people disgust me increases. Maybe self harming satisfied a part of me, the monster that would never let me be until I'd finish the punishment. Honestly most of the times I harmed I felt like there was another "me" forcing me to do it, sounds pretty dumb right. It would shame, mock and drive me to the point where I'd lose it and start the purge against myself. Then I'd get sad, cry and ask myself why did this happened, have long conversations in the mirror until that "me" would appear, would confirm that "she" is not me, but a part I keep locked inside that comes out to punish me because I never do things the right way. That I will always seek for this punishment, "she" being the one who satisfies my unconscious need. At the end says that I am just imagining this and that "she" doesn't actually exist, we debate until she drives me to tears and shaking, I'd end up rolled up in a blanket trying to stop my thoughts and avoiding the mirrors. I didn't hear from that voice from long now, although it said we merged and that we now are one. I don't come in contact with anyone, I try to be alone as much as possible and I don't feel lonely like I used to when I'd isolate myself. I tried to seek therapy, but I ended up deciding that I can on my won change and overcome this madness, so far I don't feel unhappy but the scenes I get in my head are worrying me. Should I seek for help?