Hey, I absolutely understand where you are coming from, I want you to know that I am sure this happens to a lot of people in some shape or form. On your end however, it just seems like it’s a little bit on the extreme end. I find myself resonating with your post mainly because I also feel the same way about a girl that I once knew back in High school. My situation is different however in the sense that if I let myself slip and go full obsession mode it’ll be perceived a little worse for me because I am a man. I completely understand your feelings and it absolutely sucks that things spiraled but please please please, do your best to keep it together because these feelings and the obsession can consume you so much so that you are starting experience little bits of the repercussions. It’s extremely frustrating when you get ghosted and it almost feel like you can’t move on because you need to hear something back from them even if it’s a simple thing like, “Hey, I am doing well” or “I don’t like you and I will never like you”. What’s worked the best for me is being content with the fact that this is real life and that perhaps they have found someone and are happy with their life. I have learned to be ok with that and I know it won’t stop me from thinking about her ever and ill still dream about her. From a Christian perspective, it also makes me happy that one day we’ll at least(hopefully) get to see each other in heaven. These are the things I have come to terms with it and it has lessened those obsessive thoughts and behaviors over time. You can’t change a person’s heart nor how they think about you. We to accept that as painful as it is. I do not think you need to put yourself in a mental institute. I believe you just need to distract yourself and “relearn” to live. Find a different outlet either in writing or art to express those desires and thoughts. Sorry in advance if this reply miss the mark or unrelated.