Hi There:
Yes this in usual behaviour. I am a member of another group and it is a common theme that significant others bring up and talk about. It is hard to deal with and calls for you to remain calm and to keep reassuring the person that things are okay. You have to make sure that you are listening to what the person is saying, though at times it may just be "venting", a need to get things off their chest. It can be minefield at times as at times there is a deeper issue(s) at hand that the person knows about, but just cannot get out or just doesn't know how to handle them. So the listening is important. But one thing you have to make sure is that it doesn't get out of hand and you get in the way of them trying to deal with some of their frustrations, and you become the brunt of their frustrations, that too is a common topic in my other group. Sit down with him/her and talk about how to handle the frustrations. Informing them that you want to work with them but that also means they have to work with you and your frustrations. Together hopefully you will be able to solve the issues that you are both dealing with. Keeping calm is an important key to the discussions. I found that that sometimes it was the frustrations of having to deal with the bigger issues the hardest, dealing with the masses....so to speak. Remember, it's one step at a time. That in itself is difficult for the them to deal with as they want it all and they want it yesterday and want to know what's the problem with that.
Sounds like you are doing great though. Talking/communication, staying calm and level headed is the key. That said make sure that the person knows what you are feeling as well. It's a two way street.
Gill