Where I live in the US, a 20-year-old dating a 14-year old would be illegal, and the drinking age is 21.
You were a child. It would seem to be time well spent to engage in counseling to examine / remediate an adult's use of you for her own ego, and for that matter, why your own family allowed this to go on.
If you live someplace where drinking age is 18, there is nothing wrong in deciding you wish to have a partner who doesn't drink.
It could be that you just need to decompress longer between relationships.
If the drinking age is older than 18, I think it is reasonable to be cautious about someone who breaks the law to use drugs. It may indicate dependence on drugs is already imminent. It may mean nothing.