If you are upset or having issues with a person, try doing a forgiveness which includes them. A forgiveness which applies to both of you at the same time. Forgive them, for them.
At each step of your forgiveness, as you remind yourself about what the truth is and as you undo your false belief, affirm also that this is also not true for the other person. Everything you say relating to yourself, also say it in relation to the other person. Use words like "both of us are not really guilty..." "neither of us have sinned" "we are both innocent" etc.
Take yourself and the other person all the way to the atonement, together. See how not only you are innocent and forgiven, having not really sinned, but how also the other person is innocent and forgiven, having not really sinned.
You may find that this works particularly well, because it includes a sense of joining, a sense of being equals, a sense of mutual agreement as to your mutual innocence, and emphasizes your shared interests. It also undoes any illusions you might have associated with the person as to what their attitude is, separate from your own.
Rather than forgive in isolation and only accept the atonement for yourself, claim it for yourself and your brother simultaneously.
I found this very helpful last night as I went all the way to atonement with a forgiveness about a person, seeing them as right there with me standing alongside me receiving God's love and radiating our innocence together.
Forgive yourself and your brother together and you may find it works rather well to heal a relationship.