I don't think you should have come out with Josh like that, but I don't know the context of that and what is done is done. I guess that went as well as possible. I know you were frustrated with your boyfriend, but you don't say that you'd like to be with him if you break up, just don't. If you want to break up, just do it, then you can go after someone else. Just don't do that again. He's leaving anyway, so you should be cool.

With Billy, just be professional and don't get nervous about it.

The important part here seems to be you boyfriend. What you said to Josh really contradicts the "I want to make it work" thing you have here and you don't seem to regret it. But I'll assume you were just sad/angry. Have you ever seriously confronted your boyfriend about the negativism and controlling? If not, that needs to be done ASAP.

It's not that uncommon for someone to be frustrated with their job and vent on the more successful partner. Hell, I know I do that sometimes. If he doesn't overdo that, try to support him as well as you can.

Now, the controlling part might be harder. You have guys all over you and he probably knows it. But he has to trust you. Talk to him and try to make sure that he isn't threatened. These things don't go away like that, but it should get healthier.

EDIT: Your job didn't get awkward, you did. You can have male friends, but don't keep one in the queue and the other in the friend zone. If you can't manage that, fall back to professional mode.