My friend told me I needed to get my life together. should I be mad

He basically said that I needed to figure things out, and take care of myself/my things, pointing out things that I was doing or lack of doing that I should be doing, made examples, etc. And said if I continued doing the same stupid things he wouldnt chill anymore. Should I be pissed off at him? If he's concerned, why would he be so blunt and almost short with me when he talks about it? I don't get it. I dont know if I should write him off or not.

He's probably fed up with telling you all the time. It's better to get your point across plain and blunt other than dragging it out. So... he's looking out for you, just if it bothers you talk with him about it. Ask him why.

 
You said he is your friend. Just consider if advice from a friend even if it may have been a little blunt. Value his friendship and his honesty.

the thing is, that is exactly what happened to me. She told me that I was basically wasting my life when I could be going down so many other avenues in life. And she basically told me that I was a terrible friend.

I came to her in the first place because I thought that I would be able to vent and have a shoulder to lean on. I got neither.

I wrote her off and didnt talk to her for a year. THEN realized that it was not cool for her to go about it telling me like that, but I was being just as bad by not even looking at the fact that she had probably tried to say something many times before but never did.

I forgave her. Don't let my story become yours. Take it in for what it is. Don't write him off.. trust.