how would you feel .. ?

my bf quit his job without telling me and I end up finding out from his mom. we have a 8 month old and during the pandemic i was under the assumption he was working only to find out he was getting unemployment its not until now that it bothers me because a lot financial situations we wouldn’t have had to go through if he would’ve just manned up. now i know what i know it disappoints me because why keep that away from me? we live apart simply because he can’t let go of his partying, smoking drinking days! all he does is smoke all day long and play cards til late morning and im at a point where im done. i have raised my son alone pretty much since day one. how do i tell him im leaving for good?