Every time I try to stand up for myself I fail, I can't seem to find a way to do it.
Is there something in your past that could be the cause of this?
My father used to beat me when I was a child.
I'm sorry that happened you. It's understandable you might have trouble asserting yourself. Have you thought about counseling?
I'm more assertive at work than in personal relationships. I need to speak up more at home.
It's good you're able to cope with this and have a decent work life. You also need to focus on life away from work. That's why recommended seeking counseling, it would be very beneficial to you.