Should i attend my EX girlfriend's funeral?

My EX girlfriend recently passed away. They ruled her death complications from heart failure but i suspect she died from her drug use. When i first met her she was the cutest smartest funniest and sexiest women i have ever met. At first she just smoked marijuana and that didn't really bother me because she still functioned pretty well and we had good times. She started using cocaine and i got concerned but she told me it was just recreational and she wouldn't allow herself to become addict. It did up her sex drive so selfishly i didn't do anything i should have did an intervention right then and their. She actually stopped using for a while when i told her i she could stay clean for a year i would propose. During the time her sister died in a horrible car accident and she turned to heroin. Heroin scares the **** out of me it has killed or was a contributing factor to so many of my musical heroes. I begged her to go to rehab but she refused she told me heroin gave her the strength to live and without it she would die. I tried a failed intervention tried everything i could think of the point of where i had to get out or something terrible was going to happen. She called me at 3 in the morning recently begging me take her back. I told her i loved her but unless she gave up the drugs i couldn't be her boyfriend. I heard from her mother she was in rehab because she missed me. She singed herself out after 3 days went back to her apartment and the next morning she was found dead. I feel like i should attend but it will be hard for me to see her like that and i partially blame myself for not doing something sooner rather than later. Should i go or not?