<human>: Provide a brief overview of the text.

I don't know where to start, please for give me if it's a mess to read.

7 or 8 months ago my best friend started to date this girl. He didn't know her prior at all. He dropped his life to spend every moment with this girl. A week in he told me thinks he's going to marry her. Good for him right? I was perplexed and didn't say anything when he told me this. 

This is his second serious girlfriend (his first one lasted a year and was while he was in high school) and 4th girlfriend all together. He has a tendency to get depressed when he's lonely and starts to crave attention. Ever since he started to date her he slowly shut all of his friends out and even more so me. I can never see him any more. He spends all of his free time with her and he texts her like his heart pumps blood.

He's moving in with her very soon and I'm worried that he's moving really fast. The last time I saw him I spoke to him about this and he seemed fine. Two days ago I saw him again and he was extremely rude. He told me to stay out of his business and he's finally happy. 

I just found out his girlfriends hates me and she is the reason I can't see him much at all. He's attached to this girl and views her at his savoir. I just want my friend back. 

She recently went around to all of our friends and told them I tried to make him cheat on her and how I'm a slut. He doesn't believe me when I attempted to tell him this.

I don't know what to do to show her that I'm not a threat. Is there any way I can show him he's moving way to fast with his girlfriend? I don't want to see him crash a burn.
<bot>: Friend of 6 years started dating a new girl (second serious relationship). He makes her his whole world and drops everything for her. He shut out everyone for her. She also apparently hate me.