I'm a turtle

Yes, I am a human but figuatively a turtle- let me explain

With my past in relationships- eh, there lack of, the guys I have dated always havent been mr. wonderful. At the time in my life, I thought they were wonderful, yet when I look back, I wonder what the hell was I thinking?! So I'm 23 right now and a friend introduced me to a wonderful man. I've been talking to him, for a bit and we have been having a hard time finally meeting- one weekend something came up and this weekend he had to go into work (for a bit). Well I have been so excited to meet him and I was looking forward to this all week and I even told the girls at work- which I  rarely talk about my personal life at work- and at first on friday night he said wasnt sure what time he is avaible tomorrow (ie saturday) and he would text me in the morning. Morning came and I had a text messge waiting for me and he said that He got called into work and can we move it to later today. I was crushed AGAIN and I didnt think and I just wrote, "WE CAN JUST FORGET ABOUT IT." I was so mad. He texted me later apologizing and asking why I was so rude about it. That was the end of my string and I blew up at him and said finally" You're a nice guy. Go find another girl who can deal with your crazy schedule and your lifestyle. Our lifestyles are completely different. We  just wont work. good bye."
WHY DID I SAY THIS?!?!

Then later that night  I texted him" I'm stubborn, irrational at times, i jump to conclusions way too early. I'm sorry. I was rude and arrogant. I try to protect myself from getting hurt and i push people away. i'm sorry. :("
 He says in paraphrasing- i have no idea what that has to do with me pushing us hanging out by a few hours. all i could say was i was just trying to apologize and explain why i did that. I havent heard from him since.
I screwed up royally with this guy. I am the first one to admit it. I jumped down his throat and not even asking any questions such as " what time were you thinking?" or " oh okay, maybe tomorrow?" no I just jumped to the conclusion and shut down

Now I am getting to the point of me being a turtle. When ever a guy got close to me and I got the feeling he was getting to know me too well, I would shut down and block him out IE. I would crawl back into my shell and try to forget about it.
When ever I think someone is trying to change my world aka my bubble, I get scared and i run away. I only do this in my dating life- go back into my shell and try to forget about what happened.

I am a turtle and I need help with it. =/