I think you should be concerned that you are thinking of settling down with someone who is clearly addicted to drugs. Do you know much about cocaine addiction? I suggest you go read some of these threads and how damaging this drug is to families – bringing children into hell (because that’s what it is) is not cool!!
The impotence could definitely be down to long term usage of this drug!
Probably be best to do some independent research and find out for yourself the affects.
Cocaine addiction is awful and dangerous so id say be careful with what path you wanna go down here.