Hello & welcome. Are you considering moving back in with him?
You asked how you can tell if someone has changed.
If he has the money he still does cocaine. You know he is still drinking. He also uses the excuse of being lonely and misses you to drink.
I would not trust him with my child alone either.
It doesn't sound like he is doing anything different than he had been when you were with him.
Doesn't seem like he's making much of an effort to stop his addict behavior. Counseling , support groups, AA, NA, church,
He will need help when he wants to finally stop using. He needs to take responsibility and not blame or use someone else as his excuse to use or drink.
I would suggest you get to a support group for yourself.
Al-anon is a support group for the loved ones of addicts.
Let us know how you are doing.