Question Of The Night...

TAYY • 👨‍👧‍👦👩‍👧 Small Business Owner Poverty Prevention Consultant👩🏽‍💻
I have recently been talked down on by my mother because of my situation with my current boyfriend. 
  I have been dating this guy for 3 years in November, and we have a 7 week old son. My boyfriend was "providing" for our household up until about 4 weeks ago. He lost his job but even when he had his job, he spent all his money on the wrong things.. like we almost got evicted from our apartment because he spent him money on other things instead of rent. 
He is 20 years old, 21 in December. 
I turn 21 in October. 
   I recently went on a job search so I could pay our bills, as he looked for a new job as well, I got hired on at a grocery store part time. So I could still care for my son. 
Now that I'm working my boyfriend is asking me for money to spend on himself. And I always seem to give in. 
My mother doesn't want me in this relationship for exactly that reason. She said he is living off me, that it should be the other way around that I should be at home caring for my son. 
Because even while I'm at work my boyfriend doesn't have our son, my grandmother of mother does.. 
I am the only one with a car at the moment, he is so bad with his money he can't even save up to get his license, so when I buy a new car, he still won't have a way to work if he don't get his license..
I just don't know what to do. I am honestly getting fed up, I gave him some money tonight and I told him that this is the LAST time and if he asks again my son and I will pack up and go our own way... 
** What would you guys do if you were in my situation, and REALLY think about if it was your husband or partner. Don't stunt for the media I want to really hear your opinions. 
-Would you try to help him ?
-Leave him ?