I have a feeling that relationship will change for the better over time. In the mean time, try to lessen your contact and that way you won't be in a position to agrivate each other. As you get older and you learn better how to get along with each other, you can get back to more normal interaction.
To get along, you will have to exercise some tips. Firstly, take some deep breaths before you act on something your brother may have done to you. Secondly, don't let their words get to you and then give them space when it happens. Another idea is to talk to your mom about it and let her discuss it with both of you.