Stick it out or leave ?

4 1/2 years... started like normal love sparks lots of passion second year in anger sets in he loses his temper got physical. 3 times that year. Next year 3rd twice.. 4th year twice. Not sure if it’s because I feel like it’ll change or if this time he honestly let go of his anger. I haven’t seen it in about 2 months now. I feel dumb and I’m scared what should I do ? His mom tells me she went through it with his dad but it doesn’t happen anymore and hasn’t for well over 3 decades.