If someone constantly keeps blaming you, then do not care about it.
It happens so often, when mothers constantly blaming their children, the children stop caring about what their mother is saying. This is because they know she is going to continue the same behaviour every day, right?
The trouble happens when someone who never complains suddenly complains. When someone who is never rude suddenly becomes rude, that bothers you more, isn’t it so?
Either you are eternalizing the problem, or you lack the skill to deal with what is happening. These are the only two aspects to it. So skilfully handle these situations and do not eternalize them.
Everybody has a right to be a little imperfect. You should accept others’ imperfections and your own imperfections as well. When you do not accept peoples’ imperfections, you get angry. And when you do not accept your own imperfections you feel guilty and then you become angry at yourself. Both situations are not healthy and congenial for you. So, you need to keep a little space in life for imperfections, and just move on. Do not get stuck in the past.