What should I do??

So my husband of 10 yrs doesn't want to have sex like... ever... he is an alcoholic so his levels are in the grave yard... we have talked about this situation but he don't care.... he has no interest in fixing our situation.... meanwhile he's always complementing and messaging other females online ( and has cheated infinity of.times) .... this has been going on for years.... I already told him it's over... but he doesn't move out ... its my parents house where we rent .....I'm like so close to cheating but I'm a good person.... idk what to do