Hi there Lea...
It sounds like you are going through a very difficult time, somehting that i can't evin begin to understand fully as I have no siblings so the loss of one is nothing i have ever experienecd. But i do have some advice for you that I Sincerely hope will help you get through this.
You say your problem is psychological, thats only partly true. modern thinkin has seperated the body ionto compartments that are to be seen as seperate, the the mind, the body and the 'soul'. To me this is a terrible thing, as it has removed the understanding that we are wholistic beings, and troubles in one part of the self can lead to troubles in another part.
With regards to the knob in your throat, that's from the anxiety. But it is also telling you so much more. There is trouble in your throat chakra, whis is the chakra of communication. So you possibly need to look at things from this perspective. It is nearing 1 year since your brother passed on and this is certainly on your mind. It may be possible that you ant to talk to your brother, but problem is, he is no longer in this reality. Well thats not a problem at all. Whether you believe in reincarnation or not, you can communicate with him, and vise versa. How? The way i understand it is that a persons higher soul always leaves traces of itself in the spirit world, and it is these traces that we can communicate with.
It may be your brother is trying to tel you something, or you may want to tell him something. This does not need to be anything in specific, just a hello. So what i propose you do is, every night when you go to bed, sit and talk to him. Tell him how your day was, that you miss him, how things are at home. He probably already knows thee things but this is so that you can reistablish the lost connection to him. Dont try and push him out of your mind. Acknowledge him in your thoughts. Also, acknowledge your emotions. If you feels sad and blue sometimes, feel sad and blue. We are human and humans experience emotions. But these sad feelings should not run your life. Your brother is in an amazing place, and his soul is free from the pains of this world.
So talk to him, express yourself. This will not be easy at first, in fact it will probably be quite difficult. But stick it through. You might want to also include him in your rituals. The powers of our ancestors are amazing, and it is alsays nice to have a loved ones spirit with you in circle.
I really hope that this helps and you can make some peace. There is so much more i would like to say, so if you want to ask anymore questions feel free.
May peace be upon you.
Bartimaeus.