Relationship 😟

I have been with my boyfriend for 4 years....I do love him but the last 2 years he has been abusive not physically but mentally..he always calls me names in front of my kids...like a worthless mom, slut, bitch etc. He always talks down to me...I want out of the relationship but I don't think I know how to...I'm sick and tired I believe I deserve more respect then that...we do have a child together & I feel like I force myself to stay because of that reason...also I have a child from a previous relationship & I feel like he doesn't like her...I'm always having to take up for her cause he constantly cause her a brat....please help? Advice? Opinions?