do you think it is right for a guy to get with asingle mother and plat daddty yo her child?

i got with this guy about 5 months ago and he kneew i had a child and he said he didnt care. i am a single mother and he wanted to be my kids dad.i dint mind the idea but now he is more concern of himself and his habits than he is to be my son dad like HE wanted to .
i am 18 and he is 24 my son is 10 months old any help would be apperated.