Is your co-worker/associate mean or insane? For if one has a mental health condition you would sorta understand their outburst and not take it so personally but if their mean well then you need to stand up for yourself more forcibly. I believe these factors (below) will help you determine which is the person you are dealing with. Either way there is no reason to sit and take the abuse from such a toxic relationship and distance might be the one solution which could work in both scenario’s.
(1) EVERYONE- Do other’s complain about the person’s tone and tenor? If so then they probably have a “problem” that you didn’t start or will finish.
(2) SAME PATTERN- As Mr. Einstein said if your associate continues to do the same thing and expect a different outcome well then he/she should see someone else instead of arguing with you.
(3) CHANGE- On the other hand if the person looks to attack you well then it could be they are a bully that has never grown out of high school and are just mean.