After a year of no contact I reunited with an old friend of mine. We've known each other for 4 years. We started hanging out again last Sunday and have spent around 10 hours a day together since. I can't seem to stop thinking about her. I started having sleeping problems where I can only get around 3 hours of sleep each night. My friend pointed out that it started Sunday night. I always cared about her as a friend and had feelings for her at one time. I don't know why I can't stop thinking about her now. Shes dating a jerk right now. He has hit her and constantly cheats and threatens to leave her. I don't know what to do. I have never felt like this before. It really sucks having a person you feel you really care about right next to you and you feel you can't do anything about it. For the past few days I haven't even been happy until her daily visit. Shes very friendly and cheerful. I've never met a girl like her in my entire life.