Is it normal i am worried i will never find new friends again? (long!)

Maybe I am simply not cut out for the job. -___-

Sigh, how to begin...

My former four best friends in the world turned their backs on me after I decided to finish my degree. After a prolonged period of tension caused by jealousy and spite, they simply vanished from my life and did not want to have anything to do with me. I have known these people for 10 years. I did not expect a thing, and I still do not fully comprehend why this happened. My friends where like family to me. To be dumped by them all of sudden, without warning... Was a dagger through the heart. I have asked them over and over again- what did I do wrong? They have yet to give me an explanation of what happened.

Eventually I started meeting new people. I did find new people to hang out with, but that did not work out too well either. Firstly, I seem to have a hard time finding people that are genuinely interested in me. Secondly, one of my new friends has started to show symptoms of extreme jealousy as well. I have tried everything by the book: ignoring negative behavior, complementing the other person, avoiding certain no-no topics with people and even not mentioning personal success in my life at all. All my attempts were in vain. I now occasionally talk to her on Skype, and simply ignore the snappy, uncalled for remarks- I never see her in person any more because her competitiveness and insecurities about her appearance eat up all of my energy.

***

I could pretend I simply do not care, but I am genuinely hurt by all of this. I do not know why I tend to pick people who either become jealous or disinterested over time. I blame myself. I have started to think that I have very poor judgment when it comes to people, and it makes me feel very insecure about myself. I know this is not true - I usually have very good instincts about people - just not when it comes to friendship! I care about other people, I like to socialize. Yet I have started to wonder: do I care too much?? Do I simply have to become a coldhearted bitch that talks down on people to get people to like me? Am I just naif when I say I simply accept other people the way they are, and expect to be treated like that as well?

A lot of people think I am an attractive and high-achieving person. (I am basing this literally on what others have told me). However, most of my friends of the past where smart and beautiful people too! My former new friend was a model! And she used to be a honor student, just like myself! I did not do anything to provoke their behavior, I was not overly happy or proud, nothing of the sorts! I have always been there from them, we always had a good time.

Where are the red flags everyone keeps telling me about? :(

I am sad as I am writing this, because I realize how distrustful I have become of people. I have been through so much backstabbing and drama (too much to explain in this post), that I have started to think people are simply not worth the effort. Just thinking about this makes me feel depressed.

**I apologize for the long explanation, but I had to get this out of my system. I also apologize for any typos and bad grammar- I am a non-English speaker.**