At what point is enough, enough??

So I (43f) have been with my significant other (39m) for a little over a year. We've been through a fu*king LOT together. His health issues, my health issues, his alcoholism, my health issues... I mention my health issues twice because that seems to be his reasoning behind a lot of what he's doing. I've caught him multiple times messaging other women behind my back as well as sending and receiving nudes. Every single time we come across this, he always apologizes and cries and begs me not to leave him or kick him out. We are not very intimate, normally only sexual maybe once or twice a month (his choice), and when we do he always wants to do it from behind me (which doesn't get me off at all). Anywhoos, today was another one of those days. He even went so far as to tell me that he contacted a family member and asked to stay with them for a few days until he could figure out another living situation. Come to find out this was a lie. He didn't contact anyone and didn't ask anyone to stay with them, he just told me that to manipulate me. I love this man with all my heart and soul, and apparently I'm loyal to a fault because I cannot let him go. At what point does love become not enough?? Love cannot hold anything together if there's no trust right? I honestly dont know what to do anymore.