Depression getting worse

(sorry it's so long) I'm having a very hard time lately. My daddy passed away thanks giving day. I was 45 minutes away in a different state when I got the call he was on life support and I needed to come home. I was 20 minutes late.... When I got there they told her was gone and it had happened 20 minutes before I could show up. I unfortunately for not have my own car and I'm 19 years old. They told me I could go say my good byes then the hospital would have to take him to the morgue. I was and still am devastated. Then came his arrangements. I am his only other kin so I had to make the choices and it was hard considering everything like he had no will and I couldn't get the way he looked out of my head. When I seen him in his hospital room he was yellow and he still had all the tubes and his eyes were still open. He was so cold to the touch. But I did my best and tried to pick what I think he would like. He had been dating this lady for like maybe a little more than 6 month's and she had moved in because her house foreclosed. I thought she was nice and sweet but I guess people aren't what they seem. While making his arrangements we (my family on his side) decided it would be best for everyone to get him cremated. I thought since she helped my dad while she was there I would put his gf in the obituary just to be nice. Well I regret it. Now considering everything thing else I'm going through she is trying to keep his stuff that is rightfully mine away from me. And I'm 100% positive she is selling his stuff and stealing stuff. Today I tried to get it and she wouldn't let me in and we called the cops. Today is the day I lost all trust in the law. They had failed me. They said I can't do anything till I go to court and even then they doubt anything will be done. So along with the pain of losing him I'm losing the things he had wanted his grandson which is his only grandchild (my son) to some lady that did this to her husband and his family when he got sick and died. Her son even threatened my aunt my dad's sister with a gun and nothing was done. Plus my anxiety and depression have gotten 100x worse and I'm pretty sure she is still thinking she gets to come to his ceremony tomorrow. I feel like my body is gonna shut down plus I haven't slept but 12 hours in five days and I am starting to loose it.