Called the cops on my own sister

I’ll keep the store short. My sister is a drug addict who has 4 kids but only has custody to 3. (Has not seen the oldest for obvious reasons). I came from Virginia Beach to Florida to visit her and believed her when she said she was not using anymore. Her actions disapproved otherwise. She would whisper to her husband “come here” and they would go to their room multiple times and shut the door. Her husband would randomly go next door or leave to go to the “store” multiple times. Then apparently someone owed her husband money and he went to get it at 11pm on a week night. I was supposed to go there this morning for an early thanksgiving but she texted me this morning saying “don’t come yet Nate (her husband) and Michelle (his sister) are laying around like they are dying” this sister is known for drugs too and she spend the night. All of them are in their 40’s and have kids. My sisters kids are still in school. I called the cops after I got that text because I’m not a beginner to knowing when my sister is using but they said I have to call CPS which I plan on doing. I decided not to go over there today and just go back home to Virginia Beach. I tried again to have a relationship with her. I am hurting by grieving my sister and hurt for the kids. Am I overreacting or does it sound like she’s using? Should I beat myself up over walking away? I don’t know how I can have a relationship with someone when I don’t know who they really are. I plan on helping the kids as soon as I get back home