Should I be scared of my ex-boyfriend?

I recently broke up with my boyfriend because we were just not compatible. He was controlling, jealous and had an anger problem at times. At the same time, he was loving and treated me well in other areas. I understand that this does not make the controlling behabiour justified.

Right after the break up he was okay. The next day he freaked out at me on the phone, called me names, and told me he never wanted to hear from me again. The next day after that, he told me he wanted to "rip me to shreds" because I made him so angry. Couple days later, he got to the point that he said the whole break up was his fault and he wanted to make it up to me and change to be a better boyfriend - a complete turnaround. He said he realized it was all his fault and wanted to make it up to me.

He showed up at my office and would not leave until I came outside. He said he would stand there all day if he had to. I finally went outside and found that he had bought me my favourite meal for lunch. This was his first attempt to show me he had now "changed." "This made me very uncomfortable that he showed up at my work. He also sent a bouquet of flowers to my office the next day with a note saying that he would do whatever it takes to make it up to me.

When we met up to talk about the breakup the next week, he wrote me a 3 page letter about how he wanted to change. This was all so confusing because at first, it was all my fault not his.

He kept talking to me like we were still dating (nicknames, kissy faces, etc.) and I told him to stop. This made him angry. I told him I was okay to be civil but nothing else (which I had said since the day we broke up). He called me 17 times within 5 minutes when I wouldn't pick up after he got angry over text about me asking him to stop. When I finally picked up he told me that he was going to ruin my life as he no longer has any empathy for me. He said I crushed his heart so now he will ruin my life. It has been almost 2 weeks of no contact from both ends. Should I be worried that this 2 week no contact period is just leading up to something dangerous? Or is he really going to leave me alone now?

He is a very career oriented man with a good job and I don't think he would jeopardize that by harming me. It's been 2 weeks since he has contacted me. Is this a good sign?

Woah! You were dating my husband I think maybe, lol.
I could have written that story, word for word, on three different occasions! You see, I did go back to mine eventually every time. Usually during the "got my favorite lunch" phase... bad idea, don't try that...
I honestly can't say, since I don't know him personally, but I would definitely be very careful. Have you told anyone about this behaviour? I am not suggesting that you go blab your dirty laundry all over town, but a couple of close friends should know at least. You might want to consider telling some key people at work a little about your situation, and ask them to keep it in confidence, but not to give out any information about you to this person, or to forward his calls to you or let him into your office. A restraining order might not be a bad idea if that is an option for you.

Does he have access to any firearms? Does he have a history of violence or animal abuse? Those things do factor in, and I am learning, are often indicators of a more serious situation than just threats.

Hopefully he has cooled down and accepted facts as they are, and will leave it at that.

Maybe this could help? http://www.psychforums.com/domestic-abuse/topic11734.html