Jealous and Insecure Boyfriend

I love my boyfriend, (A); I really do. I just have reached wits end with him. Goodness gracious, I don't know what to do anymore.

This all started when my friend from the UK (a guy, we will call him N) announced he was coming to the States for six months due to work, and of course, he wanted to see me. Wonderful, I get to see my friend! However, that was pretty much robbed from me.

(A) started to get all freaked out saying that N would take advantage of me and or put me in a bad situation where he couldn't help me. He thought I was going to cheat on him with this guy. He spewed this utter malarkey that he "trusts me but not other people." To try and make everyone happy I asked N if he could meet my boyfriend because that was going to be the only way to reassure my boyfriend.

Surprise, surprise, N has a crush on me and obviously split from the scene at the request. (A) got all freaked out that another guy has a crush on me and since then has been insecure as all get out.

Let's get something straight. I spend 50% or more of my time with this man, which isn't a bad thing. I talk to him and text him all the time. I snap him and tag him. All this hoo-ha. Yet, he's still insecure.

"I'm afraid I'm losing you."
"I don't think you're happy with me."
"I'm a terrible boyfriend. I don't do anything right."
Etc. Etc.

Then on top of that, I've slowly started to rebuild things with N, but it's pretty much start over we're just acquaintances now. He doesn't want to get close because of my boyfriend and said to me, "I don't want him to freak out over me."

Even with that relation in shambles, my boyfriend is still freaking out. He won't let N go either. "How's N?" I wouldn't know since he's hesitant to even talk to me!

I'm trying to reassure him that all is well and that he is a good boyfriend. He really is a good one, if only he could get outside of the jealousy and insecurity! It's really pushing me away. I'm afraid to tell him that because he'll probably freak out even more @_@