My husband goes out partying all night leaving me with our two children

My husband and I have been married for six years, we have two children aged 3 and 9 months. He started going out all night while I was pregnant with our first child, I assumed that he was anxious about us having a child, although setting approximate times he should be home. It got so bad after our 1st child, after arguing , talking about it calmly,nothing changed. I went out all night and he slowly stopped, He starting doing it too me again, I am a lot stronger now and think is unacceptable.I don't feel like raising our children is my sole responsibility. Any ideas or sugestions would be gladly received