I used to be so meek at work, just accepting any old crap off anyone, doing my work and going home. Rinse and repeat Monday to Friday. Last week someone of the same level as me, tried to give me some of his extra work and I told him ''No, do it yourself" He told me I was disrespectful and he was going to report me. I got up from my desk and slammed my mouse down, and walked away. He reported me. We had a 'big' meeting with our boss who said we had to get along and they will be reviewing it in a week. I basically just want to stay at home under the duvet and never go back but I have to.
How can I be more assertive with this man? I just feel depressed and alone.