Help my partner keeps diasappearing and reappearing.

I am 30 years old and I have been with my partner for eight years. We have two children, aged three and eight years.
When I conceived my first-born, I lost my job. My partner got an apartment, paid rent for one month and disappeared.
When my first baby was one month old, I got another job. After six months, my partner found out my workplace from my friends.
He apologised for his behaviour and I forgave him. Shortly after that, he disappeared again for five years.
I got a better job and he came back claiming he had joined the army. I asked him to visit my parents, but he declined to do so, saying he was broke.
During that time, I conceived our second child, but he fled again.
He came back when our second-born was six months old and said he had joined the army. He does not support me.
I take care of the children single-handed.
Should I leave him? Can I manage as a single mother?