My boyfriend says I have anger issues

So like the title says my boyfriend thinks I have anger issues and I take them out on him then I had a dream in which I lost my family because I kept taking my anger out on him and I was hurting his feelings so he left ik it's just a dream and some dreams have no meaning but this dream felt different I called him and talked to him and he said that I do take out my anger on him even though he's not the person to make me mad so my question is how can I not take out my anger on my boyfriend? I've researched some methods and I will be trying timeouts where I give myself five minutes (while I'm angry) to calm down and not talk to him.